Recent Developments and Applications in Analytical Chemistry

**119**

**Chapter 6**

**Abstract**

**1. Introduction**

Diseases

Aptamers for Diagnostics with

Aptamers are in vitro selected oligonucleotides (DNA, RNA, oligos with modi-

fied nucleotides) that can have high affinity and specificity for a broad range of potential targets with high affinity and specificity. Here we focus on their applications as biosensors in the diagnostic field, although they can also be used as therapeutic agents. A small number of peptide aptamers have also been identified. In analytical settings, aptamers have the potential to extend the limit of current techniques as they offer many advantages over antibodies and can be used for real-time biomarker detection, cancer clinical testing, and detection of infectious microorganisms and viruses. Once optimized and validated, aptasensor technologies are expected to be highly beneficial to clinicians by providing a larger range and more rapid output of diagnostic readings than current technologies and support

personalized medicine and faster implementation of optimal treatments.

of nucleic acids other than storing and transferring genetic information [2].

against targets varying from small molecules to cells using SELEX [3].

**Keywords:** aptamer, SELEX, biosensors, aptasensors, diagnostics, infectious diseases

In 1868, a young Swiss physician Friedrich Miescher isolated a new biological compound from nuclei of white blood cells, which had not been described before. He named it "nuclein" [1]. Today, it is known as "deoxyribonucleic acid (DNA)" which is nucleic acid in nature and carries heritable information for biological organisms. However, with advancements in the molecular genetics field, scientists started to discover new functions

In the 1980s, research on human immunodeficiency virus (HIV) and adenoviruses revealed a new understanding of the importance of selective interactions between nucleic acids and proteins. These studies demonstrated that viruses express small RNAs, which bind to cellular or viral proteins with high specificity. In parallel with these discoveries, scientists focused on deciphering fundamental features of short RNAs that can fold into unique three-dimensional structures [3]. In 1990, three separate groups [4–6] invented the systematic evolution of ligands by exponential enrichment (SELEX) method by which they obtained nucleic acid molecules, similar to naturally occurring nucleic acids, which have high specificities and affinities toward their targets. They named these in vitro selected molecules "aptamers." Since then, researchers have selected numerous aptamers

Applications for Infectious

*Muslum Ilgu, Rezzan Fazlioglu, Meric Ozturk,* 

*Yasemin Ozsurekci and Marit Nilsen-Hamilton*

#### **Chapter 6**

## Aptamers for Diagnostics with Applications for Infectious Diseases

*Muslum Ilgu, Rezzan Fazlioglu, Meric Ozturk, Yasemin Ozsurekci and Marit Nilsen-Hamilton*

#### **Abstract**

Aptamers are in vitro selected oligonucleotides (DNA, RNA, oligos with modified nucleotides) that can have high affinity and specificity for a broad range of potential targets with high affinity and specificity. Here we focus on their applications as biosensors in the diagnostic field, although they can also be used as therapeutic agents. A small number of peptide aptamers have also been identified. In analytical settings, aptamers have the potential to extend the limit of current techniques as they offer many advantages over antibodies and can be used for real-time biomarker detection, cancer clinical testing, and detection of infectious microorganisms and viruses. Once optimized and validated, aptasensor technologies are expected to be highly beneficial to clinicians by providing a larger range and more rapid output of diagnostic readings than current technologies and support personalized medicine and faster implementation of optimal treatments.

**Keywords:** aptamer, SELEX, biosensors, aptasensors, diagnostics, infectious diseases

#### **1. Introduction**

In 1868, a young Swiss physician Friedrich Miescher isolated a new biological compound from nuclei of white blood cells, which had not been described before. He named it "nuclein" [1]. Today, it is known as "deoxyribonucleic acid (DNA)" which is nucleic acid in nature and carries heritable information for biological organisms. However, with advancements in the molecular genetics field, scientists started to discover new functions of nucleic acids other than storing and transferring genetic information [2].

In the 1980s, research on human immunodeficiency virus (HIV) and adenoviruses revealed a new understanding of the importance of selective interactions between nucleic acids and proteins. These studies demonstrated that viruses express small RNAs, which bind to cellular or viral proteins with high specificity. In parallel with these discoveries, scientists focused on deciphering fundamental features of short RNAs that can fold into unique three-dimensional structures [3]. In 1990, three separate groups [4–6] invented the systematic evolution of ligands by exponential enrichment (SELEX) method by which they obtained nucleic acid molecules, similar to naturally occurring nucleic acids, which have high specificities and affinities toward their targets. They named these in vitro selected molecules "aptamers." Since then, researchers have selected numerous aptamers against targets varying from small molecules to cells using SELEX [3].

#### **1.1 Systematic evolution of ligands by exponential enrichment**

SELEX is a technique to isolate an aptamer that is specific for the desired target from a randomized oligonucleotide (oligo) library by simulating evolution (systematic evolution of ligands). This in vitro technique includes a number of selection rounds (between 5 and 20) alternated with exponential amplification of the fittest oligonucleotides by PCR for DNA libraries or RT-PCR for RNA libraries (exponential enrichment).

In a typical SELEX experiment, the starting pool contains up to 1015 random oligonucleotide sequences. These sequences in the pool have a unique three-dimensional (3D) structures defined by the combination of interactions that include base pairing, stacking, sugar packing, and noncanonical intramolecular interactions. This structural complexity in the pool establishes a high probability of selecting an oligo that can interact avidly and specifically with the target of interest (aptamer). The intermolecular interaction between aptamer and target may include hydrogen bonds, salt bridges, van der Waals, and hydrophobic and electrostatic interactions.

Traditionally, SELEX is comprised of three main steps: incubation, separation, and amplification. The process involves incubating a "library" of oligos with randomized internal sequences of 20–60 nt with target molecules for a chosen period of time. Removal of unbound oligos from this mixture completes this initial step. Oligos that remain bound to the target are separated and amplified either by PCR or RT-PCR depending on the oligo type, DNA, or RNA. For DNA SELEX, biotin-labeled primers can be used in PCR, and the resulting double-stranded forms are separated using methods such as streptavidin bead capture. For RNA, T7 RNA polymerase promoter-containing primers are used in RT-PCR after which RNA libraries are amplified by in vitro transcription. The protocol follows the same amplification steps for several rounds (4–20) as for DNA SELEX (**Figure 1**). Negative selection can be included in either RNA or DNA SELEX protocols, which is achieved by passing the nucleic acid pool over a supporting matrix in the absence of the target. This step aims at eliminating the oligos that bind the matrix in a targetindependent manner. Analogs of the target can also be included during selection rounds as competitors of binding if there is a means of separating the target from the analog competitors. This competition is expected to result in aptamers with higher specificity for the target over the analogs.

Two alternative protocols are followed after these rounds to complete the SELEX. The selected oligos from the final round are cloned and sequenced for aptamer identification. Alternatively, high-throughput sequencing (or next-generation sequencing) can be employed to obtain sequence data from oligos present in the pool after different rounds of selection. Comparative sequence analysis allows pinpointing

**121**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

consensus sites that are potentially involved in target recognition [7, 8]. The most promising sequences are synthesized and characterized further, among which aptamers with nanomolar dissociation constants are frequently identified. In some instances,

Aptamer selection directly depends on environmental components during SELEX. This is because the ionic components and pH of the environment can dictate the predominant structures of oligos in the pool. Nucleic acids are negatively charged molecules that create an "ionic atmosphere" for ion-nucleic acid interactions, a freely joined sheath of ions surrounding the nucleic acids. These electrostatic interactions directly affect the structure of nucleic acids and thus the target binding by changing charge distribution. For specific ligand binding, it is crucial that the aptamer reliably forms the appropriate three-dimensional (3D) structure. However, structures of short oligonucleotides like aptamers are affected by the incubation temperature and the components of the operating buffer system such as the specific ions, ionic strength, and pH. Therefore, the affinities and future performance of aptamers depend on the buffers used during aptamer selection, and the choice of buffer present during selection requires attention when developing a SELEX protocol [10–13]. Some factors present in the samples to be analyzed may have a negative impact on aptamer performance. For example, aptamers are susceptible to nucleases that are present in many biological samples. This is particularly true for RNA, having the 2'OH group, which can electrophilically attack the phosphate of the nucleic acid backbone. Nucleases promote this chemical property to catalyze hydrolysis of RNA, and this property also makes RNA more chemically labile to high pH and temperature compared with DNA. To counter this susceptibility to hydrolysis and to stabilize nucleic acids, many post-selection chemical modifications can be made. However, incorporating these modifications into the aptamer after its selection carries a large risk of altering the aptamer structure with a resulting loss of affinity for the target analyte. Alternatively, the less risky approach is to use chemically

Secondary motifs in the tertiary structures of aptamers are diverse. Such motifs

Aptamers have a significant advantage over antibodies as components of sensing units. One advantage is that nucleic acid structures can be regenerated several times with little activity loss, whereas protein-based antibodies can only be used once or a few times before their functionality is lost. In contrast to antibodies or enzymes,

include the "stem-loop," "hairpin structure," "pseudoknot," "internal bulge," "kissing loop," "three-way junction," and "the G-quadruplex." To understand these structures in detail, X-ray crystallography or nuclear magnetic resonance spectroscopy is utilized. But these techniques are laborious and expensive. To ease the process, computer algorithms have been developed to estimate the lowest freeenergy structures using sequence-based modeling [14]. This makes it possible to quickly predict the secondary structure of oligonucleotides without needing many resources. However, computational approaches to obtaining 3D models of nucleic acid structures by modeling from primary sequence are still in the development phase, and the results are not as reliable as experimental methods [15–17].

In vitro selection can take months. To shorten the time for selecting high affinity aptamers, Golden et al. suggested a new method for SELEX: photochemical SELEX (PhotoSELEX) [9]. The technique involves the evolution of modified DNA aptamers, which are capable of forming a photoinduced covalent bond with their targets. Thus, these aptamers have greater specificity, and fewer selection rounds are required to select aptamers compared with the traditional SELEX methodologies.

aptamers have also been isolated with picomolar dissociation constants.

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

substituted nucleotide analogs during SELEX.

**1.2 Aptamer structure**

**Figure 1.** *Schematic representation of SELEX protocol.*

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

consensus sites that are potentially involved in target recognition [7, 8]. The most promising sequences are synthesized and characterized further, among which aptamers with nanomolar dissociation constants are frequently identified. In some instances, aptamers have also been isolated with picomolar dissociation constants.

In vitro selection can take months. To shorten the time for selecting high affinity aptamers, Golden et al. suggested a new method for SELEX: photochemical SELEX (PhotoSELEX) [9]. The technique involves the evolution of modified DNA aptamers, which are capable of forming a photoinduced covalent bond with their targets. Thus, these aptamers have greater specificity, and fewer selection rounds are required to select aptamers compared with the traditional SELEX methodologies.

#### **1.2 Aptamer structure**

*Recent Advances in Analytical Chemistry*

tial enrichment).

**1.1 Systematic evolution of ligands by exponential enrichment**

higher specificity for the target over the analogs.

Two alternative protocols are followed after these rounds to complete the SELEX. The selected oligos from the final round are cloned and sequenced for aptamer

identification. Alternatively, high-throughput sequencing (or next-generation sequencing) can be employed to obtain sequence data from oligos present in the pool after different rounds of selection. Comparative sequence analysis allows pinpointing

SELEX is a technique to isolate an aptamer that is specific for the desired target from a randomized oligonucleotide (oligo) library by simulating evolution (systematic evolution of ligands). This in vitro technique includes a number of selection rounds (between 5 and 20) alternated with exponential amplification of the fittest oligonucleotides by PCR for DNA libraries or RT-PCR for RNA libraries (exponen-

In a typical SELEX experiment, the starting pool contains up to 1015 random oligonucleotide sequences. These sequences in the pool have a unique three-dimensional (3D) structures defined by the combination of interactions that include base pairing, stacking, sugar packing, and noncanonical intramolecular interactions. This structural complexity in the pool establishes a high probability of selecting an oligo that can interact avidly and specifically with the target of interest (aptamer). The intermolecular interaction between aptamer and target may include hydrogen bonds, salt bridges, van der Waals, and hydrophobic and electrostatic interactions. Traditionally, SELEX is comprised of three main steps: incubation, separation, and amplification. The process involves incubating a "library" of oligos with randomized internal sequences of 20–60 nt with target molecules for a chosen period of time. Removal of unbound oligos from this mixture completes this initial step. Oligos that remain bound to the target are separated and amplified either by PCR or RT-PCR depending on the oligo type, DNA, or RNA. For DNA SELEX, biotin-labeled primers can be used in PCR, and the resulting double-stranded forms are separated using methods such as streptavidin bead capture. For RNA, T7 RNA polymerase promoter-containing primers are used in RT-PCR after which RNA libraries are amplified by in vitro transcription. The protocol follows the same amplification steps for several rounds (4–20) as for DNA SELEX (**Figure 1**). Negative selection can be included in either RNA or DNA SELEX protocols, which is achieved by passing the nucleic acid pool over a supporting matrix in the absence of the target. This step aims at eliminating the oligos that bind the matrix in a targetindependent manner. Analogs of the target can also be included during selection rounds as competitors of binding if there is a means of separating the target from the analog competitors. This competition is expected to result in aptamers with

**120**

**Figure 1.**

*Schematic representation of SELEX protocol.*

Aptamer selection directly depends on environmental components during SELEX. This is because the ionic components and pH of the environment can dictate the predominant structures of oligos in the pool. Nucleic acids are negatively charged molecules that create an "ionic atmosphere" for ion-nucleic acid interactions, a freely joined sheath of ions surrounding the nucleic acids. These electrostatic interactions directly affect the structure of nucleic acids and thus the target binding by changing charge distribution. For specific ligand binding, it is crucial that the aptamer reliably forms the appropriate three-dimensional (3D) structure. However, structures of short oligonucleotides like aptamers are affected by the incubation temperature and the components of the operating buffer system such as the specific ions, ionic strength, and pH. Therefore, the affinities and future performance of aptamers depend on the buffers used during aptamer selection, and the choice of buffer present during selection requires attention when developing a SELEX protocol [10–13].

Some factors present in the samples to be analyzed may have a negative impact on aptamer performance. For example, aptamers are susceptible to nucleases that are present in many biological samples. This is particularly true for RNA, having the 2'OH group, which can electrophilically attack the phosphate of the nucleic acid backbone. Nucleases promote this chemical property to catalyze hydrolysis of RNA, and this property also makes RNA more chemically labile to high pH and temperature compared with DNA. To counter this susceptibility to hydrolysis and to stabilize nucleic acids, many post-selection chemical modifications can be made. However, incorporating these modifications into the aptamer after its selection carries a large risk of altering the aptamer structure with a resulting loss of affinity for the target analyte. Alternatively, the less risky approach is to use chemically substituted nucleotide analogs during SELEX.

Secondary motifs in the tertiary structures of aptamers are diverse. Such motifs include the "stem-loop," "hairpin structure," "pseudoknot," "internal bulge," "kissing loop," "three-way junction," and "the G-quadruplex." To understand these structures in detail, X-ray crystallography or nuclear magnetic resonance spectroscopy is utilized. But these techniques are laborious and expensive. To ease the process, computer algorithms have been developed to estimate the lowest freeenergy structures using sequence-based modeling [14]. This makes it possible to quickly predict the secondary structure of oligonucleotides without needing many resources. However, computational approaches to obtaining 3D models of nucleic acid structures by modeling from primary sequence are still in the development phase, and the results are not as reliable as experimental methods [15–17].

Aptamers have a significant advantage over antibodies as components of sensing units. One advantage is that nucleic acid structures can be regenerated several times with little activity loss, whereas protein-based antibodies can only be used once or a few times before their functionality is lost. In contrast to antibodies or enzymes,


**Table 1.**

*Comparison of aptamers with antibodies.*

nucleic acid aptamers are often highly stable and can be inexpensively synthesized with high reproducibility and purity. Like antibodies, they bind their targets with high affinity and specificity (**Table 1**). These properties are motivating the current flood of reports of aptamer-based biosensors employing a wide range of technologies.

#### **1.3 Aptamers for diagnostic and therapeutic applications**

Development of novel biosensors for various clinical diseases has become essential as new health issues emerged. To meet this goal, antibodies have been used extensively; however, more recently, aptamers have been recognized as promising alternatives for developing diagnostic devices.

A biosensor is a tool with the ability to provide a measurable signal as a result of biomolecular interactions. Biosensors generally consist of two components: a bioreceptor and a transducer. The bioreceptor binds specifically to the molecule of interest, and the transducer turns information from the binding event into a detectable signal. The components of the transducer include a detector and a reporter, which acts as a bridge between the bioreceptor and the detector.

The most critical part of the biosensor is the bioreceptor (or bio-recognition element). The success of the sensor directly depends on its high affinity and specificity. Because of their more flexible structures, aptamers can provide a substantial signal in combination with a larger number of detection methods than possible for antibodies. Aptamers are preferred over antibodies for biosensor applications because of their cost, stability, and reusability as well as the aforementioned advantages (see **Table 1**). Biosensors, called "aptasensors," have been developed with many detectors including electrochemical, optical, microcantilever, and acoustic detectors [10].

Aptamers are also used in therapeutic applications, which will not be extensively discussed in this chapter. For discussions of therapeutic applications, the reader is directed to reviews that focus on this topic [18–21]. The majority of therapeutic aptamers inhibit their target molecules, and some act as receptor agonists. Potential therapeutic aptamers against proteins including nucleolin, chemokine ligand 12, or thrombin have been described. Several RNA and DNA aptamers are undergoing clinical trials, yet only pegaptanib against vascular endothelial growth factor has so far been in the USA by the FDA for the treatment of vascular ocular disease [3].

To advance therapeutic applications, drug delivery systems with aptamers have been developed. For such applications, aptamers are needed that recognize cell surface proteins, which can be challenging to select because these proteins are difficult to purify in their natural conformations. The development of cell-based selection techniques has enabled aptamer selection against proteins in their native form while they are on the cell surface. These selections are performed against single-cell types [22]

**123**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

internalization in response to aptamer-receptor binding.

lites, biomarkers, and cells is possible with aptamers.

to obtain aptamers with the ability to bind cell surface proteins specifically expressed on the surface of the cell type used for selection. Delivery systems with these aptamers can carry a variety of cargos into cells by taking advantage of the surface protein

Diagnostics is one of the most dynamic fields in biosensor research. To support early diagnosis and individualized medicine, researchers seek to develop methods to detect identified biomarkers by more sensitive, time-saving, and cheaper methods. The perfect sensor for medical diagnostics should also be specific, reusable, easy to monitor, nonreactive, and stable with various biological samples. Aptamers can be developed to meet all these requirements. With their wide spectrum of possible targets, sensitive detection of virtually all toxins, drugs, peptides, proteins, metabo-

Several types of aptasensors have been developed based on electrochemical, optical, mechanical, and acoustic approaches. An early use of aptamers as bio-recognition elements in aptasensors was reported in 1996 with an optical biosensor that utilized fluorescently labeled aptamers in a homogenous assay [23]. Later, aptamers were integrated onto solid supports, which provided an opportunity for real-time analyte detection. Most of these studies have been at the proof-of-principle level, and the majority of studies have been performed with the thrombin aptamer (TA), which has the advantage of a stable target and aptamer. Thrombin aptamer self-assembles into a highly stable G-quadruplex structure, and thrombin is a structurally stable globular protein found in blood. Future studies to optimize other aptasensors with less stable aptamers and analytes in complex matrices are likely to be challenging. Aptamers fold their flexible, single-stranded chains into 3D structures, which

may change upon binding to their cognate target molecules. This structureswitching characteristic has been capitalized on in many aptamer applications. An early example used electrochemical sensing with aptamers immobilized on an electrode surface, and target binding is observed by measuring electrochemical current variations. This system utilized an amperometric sandwich assay combining TA on a gold electrode which was used to capture the TA-labeled glucose

Several types of aptasensors have been developed based on electrochemical, optical, mechanical, and acoustic approaches, which are discussed in the following

Electrochemical aptasensors are constructed by attaching an aptamer that carries a redox-active moiety to an electrode surface. Such aptasensors can make use of voltammetric (amperometric), potentiometric, conductometric, or impedimetric assays for analyte detection. In some formats, the aptamer is labeled with an electroactive group and a structural change in the aptamer upon binding to the target analyte and changes the distance of the electroactive group from the electrode surface, resulting in the switching "on/off" of the electrochemical signal. Measurement of changes in electrochemical features after target binding has been used to determine target concentration [24]. So far, electrochemical aptasensors have been reported for a wide range of targets including PDGF, thrombin and immunoglobulin E (IgE), cocaine, theophylline, adenosine, aminoglycosides, and adenosine triphosphate (ATP) and

) [10].

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

**2. Aptamer use in diagnostics**

dehydrogenase (GDH) [24].

**2.1 Electrochemical aptasensors**

inorganic ions such as potassium (K+

sections.

to obtain aptamers with the ability to bind cell surface proteins specifically expressed on the surface of the cell type used for selection. Delivery systems with these aptamers can carry a variety of cargos into cells by taking advantage of the surface protein internalization in response to aptamer-receptor binding.

#### **2. Aptamer use in diagnostics**

*Recent Advances in Analytical Chemistry*

*Comparison of aptamers with antibodies.*

**Table 1.**

nucleic acid aptamers are often highly stable and can be inexpensively synthesized with high reproducibility and purity. Like antibodies, they bind their targets with high affinity and specificity (**Table 1**). These properties are motivating the current flood of reports of aptamer-based biosensors employing a wide range of technologies.

Development of novel biosensors for various clinical diseases has become essential as new health issues emerged. To meet this goal, antibodies have been used extensively; however, more recently, aptamers have been recognized as promising

A biosensor is a tool with the ability to provide a measurable signal as a result of biomolecular interactions. Biosensors generally consist of two components: a bioreceptor and a transducer. The bioreceptor binds specifically to the molecule of interest, and the transducer turns information from the binding event into a detectable signal. The components of the transducer include a detector and a reporter,

The most critical part of the biosensor is the bioreceptor (or bio-recognition element). The success of the sensor directly depends on its high affinity and specificity. Because of their more flexible structures, aptamers can provide a substantial signal in combination with a larger number of detection methods than possible for antibodies. Aptamers are preferred over antibodies for biosensor applications because of their cost, stability, and reusability as well as the aforementioned advantages (see **Table 1**). Biosensors, called "aptasensors," have been developed with many detectors including

Aptamers are also used in therapeutic applications, which will not be extensively

discussed in this chapter. For discussions of therapeutic applications, the reader is directed to reviews that focus on this topic [18–21]. The majority of therapeutic aptamers inhibit their target molecules, and some act as receptor agonists. Potential therapeutic aptamers against proteins including nucleolin, chemokine ligand 12, or thrombin have been described. Several RNA and DNA aptamers are undergoing clinical trials, yet only pegaptanib against vascular endothelial growth factor has so far been in the USA by the FDA for the treatment of vascular ocular disease [3]. To advance therapeutic applications, drug delivery systems with aptamers have been developed. For such applications, aptamers are needed that recognize cell surface proteins, which can be challenging to select because these proteins are difficult to purify in their natural conformations. The development of cell-based selection techniques has enabled aptamer selection against proteins in their native form while they are on the cell surface. These selections are performed against single-cell types [22]

**1.3 Aptamers for diagnostic and therapeutic applications**

which acts as a bridge between the bioreceptor and the detector.

electrochemical, optical, microcantilever, and acoustic detectors [10].

alternatives for developing diagnostic devices.

**122**

Diagnostics is one of the most dynamic fields in biosensor research. To support early diagnosis and individualized medicine, researchers seek to develop methods to detect identified biomarkers by more sensitive, time-saving, and cheaper methods. The perfect sensor for medical diagnostics should also be specific, reusable, easy to monitor, nonreactive, and stable with various biological samples. Aptamers can be developed to meet all these requirements. With their wide spectrum of possible targets, sensitive detection of virtually all toxins, drugs, peptides, proteins, metabolites, biomarkers, and cells is possible with aptamers.

Several types of aptasensors have been developed based on electrochemical, optical, mechanical, and acoustic approaches. An early use of aptamers as bio-recognition elements in aptasensors was reported in 1996 with an optical biosensor that utilized fluorescently labeled aptamers in a homogenous assay [23]. Later, aptamers were integrated onto solid supports, which provided an opportunity for real-time analyte detection. Most of these studies have been at the proof-of-principle level, and the majority of studies have been performed with the thrombin aptamer (TA), which has the advantage of a stable target and aptamer. Thrombin aptamer self-assembles into a highly stable G-quadruplex structure, and thrombin is a structurally stable globular protein found in blood. Future studies to optimize other aptasensors with less stable aptamers and analytes in complex matrices are likely to be challenging.

Aptamers fold their flexible, single-stranded chains into 3D structures, which may change upon binding to their cognate target molecules. This structureswitching characteristic has been capitalized on in many aptamer applications. An early example used electrochemical sensing with aptamers immobilized on an electrode surface, and target binding is observed by measuring electrochemical current variations. This system utilized an amperometric sandwich assay combining TA on a gold electrode which was used to capture the TA-labeled glucose dehydrogenase (GDH) [24].

Several types of aptasensors have been developed based on electrochemical, optical, mechanical, and acoustic approaches, which are discussed in the following sections.

#### **2.1 Electrochemical aptasensors**

Electrochemical aptasensors are constructed by attaching an aptamer that carries a redox-active moiety to an electrode surface. Such aptasensors can make use of voltammetric (amperometric), potentiometric, conductometric, or impedimetric assays for analyte detection. In some formats, the aptamer is labeled with an electroactive group and a structural change in the aptamer upon binding to the target analyte and changes the distance of the electroactive group from the electrode surface, resulting in the switching "on/off" of the electrochemical signal. Measurement of changes in electrochemical features after target binding has been used to determine target concentration [24]. So far, electrochemical aptasensors have been reported for a wide range of targets including PDGF, thrombin and immunoglobulin E (IgE), cocaine, theophylline, adenosine, aminoglycosides, and adenosine triphosphate (ATP) and inorganic ions such as potassium (K+ ) [10].

In addition to their innate structural changes on binding their target molecules, other structural constraints can be applied to aptamers that result in signals for detection by electrochemical approaches. The most commonly used additional constraint is an oligonucleotide (either connected with the aptamer or separate) that is complementary to part of the aptamer and, upon hybridizing with the aptamer, constrains its structure to an inactive form. For example, a biotin-tagged DNA aptamer for zeatin was hybridized with a complimentary "assist DNA" to form a Y-type DNA structure. Avidin-modified alkaline phosphatase (ALP) was attached to this structure with two biotins at the terminals of DNA aptamer. In the presence of zeatin, this complex was disrupted which leads to a decrease in the oxidation signal from p-nitrophenol (PNP) produced by the catalytic effect of ALP. From this, zeatin concentration in the range of 50 pM–50 nM was selectively measured with a detection limit of 16.6 pM [25].

Redox-active methylene blue (MB) has been used as an aptamer label and electrotransfer communication agent with the electrode. Methylene blue enables the detection of changes in aptamer conformation upon target binding. For example, an MB-labeled TA was used to construct an aptasensor by its immobilization on an electrode. The flexible conformation of the aptamer enabled the electrotransfer from MB to the electrode. The structural change upon analyte binding shielded MB in a "signal-off" mode. However, this mode is a disadvantage for diagnostics because the amperometric response decreases as a result of the association of the target thrombin with the aptamer.

Several approaches have been taken to develop aptasensors that operate in a "signal-on" mode. As an example, the TA was modified with an electroactive ferrocene group as the redox label at one end and a thiol group at the other end. The electrical contact of the electrode with the ferrocene label was affected by the long, flexible aptamer chain. Thrombin binding stabilizes the aptamer's G-quadruplex conformation, which brings the ferrocene group closer to the electrode. This close proximity enables electron transfer between the electro-active ferrocene units and the electrode, thus producing a positive signal in the presence of thrombin. A similar approach to creating signal-on electrochemical aptasensors utilized the conformational change in the cocaine aptamer that occurs on binding its target. In the absence of the target, the aptamer on the solid surface stays in a partially folded form as a three-way junction. Cocaine binding decreases the distance for electron transfer and thus increases the signal [26].

Demirkol et al. generated an electrochemical aptasensor to detect *E. coli* O157:H7. The electrode surfaces were modified by cysteamine via self-assembled monolayer formation. The carboxyl-functionalized quantum dots and aptamers were conjugated to cysteamine-modified gold electrodes [27]. Ge et al. reported an affinity-mediated homogeneous electrochemical aptasensor using graphenemodified glassy carbon electrode (GCE) as the sensing platform. In this approach, the aptamer-target recognition is converted into an ultrasensitive electrochemical signal output with the aid of a novel T7 exonuclease (T7Exo)-assisted target-analog recycling amplification strategy, in which ingeniously designed methylene blue (MB)-labeled hairpin DNA reporters are digested in the presence of target and, then, converted to numerous MB-labeled long ssDNAs. The distinct difference in differential pulse voltammetry response between the designed hairpin reporters and the generated long ssDNAs on the graphene/GCE allows ultrasensitive detection of target biomolecules [28]. Lai et al. proposed a renewable electrochemical aptasensor for super sensitive Hg2+ determination [29]. The novel aptasensor, based on sulfur-nitrogen co-doped ordered mesoporous carbon (SN-OMC) and a thymine-Hg2+-thymine (T-Hg2+-T) mismatch structure, used ferrocene as signal molecules to achieve the conversion of signal to current. In the absence of Hg2+,

**125**

**2.2 Optical aptasensors**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

the thiol-modified T-rich probe 1 spontaneously formed a hairpin structure by base pairing. After hybridizing with the ferrocene-labeled probe 2 in the presence of Hg2+, the hairpin structure of probe 1 was opened due to the preferential formation of the T-Hg2+-T mismatch structure, and the ferrocene signal molecules approached the modified electrode surface. Sulfur-nitrogen co-doped ordered mesoporous carbon with high specific surface area and ample active sites acted as a signal amplification element in electrochemical sensing. The sensitive determination of Hg2+ can be actualized by analyzing the relationship between the change of oxidation current caused by ferrocene and the Hg2+ concentrations [29]. Finally, Wang et al. combined the strengths of advanced aptamer technology, DNA-based nanostructure, and portable electrochemical devices to develop a nanotetrahedron (NTH)-assisted aptasensor for direct capture and detection of hepatocellular exosomes. The oriented immobilization of aptamers significantly improved their accessibility to suspended exosomes, and the NTH-assisted aptasensor could detect exosomes with 100-fold higher sensitivity when compared to the single-stranded

Recently, nanoporous metal surfaces have been found as good sensor platforms for aptamers. Nanoporous gold [31, 32]-based sensors have been used with the TA and ATP aptamers and a redox probe to provide the electrons to the gold surface for sensitive detection of analyte by electrochemical impedance spectroscopy (EIS). The ATP aptamer was in a split format with the second half of the aptamer covalently linked with 3,4-diaminobenzoic acid (DABA), which created the EIS signal by its oxidation at the gold interface. For an analyte that can undergo redox reactions, such as bisphenol A (BPA), this property can be used to provide a signal [33]. Other nanoporous surfaces such as graphene oxide/Au composites and porous PtFe or PtTiAl ternary alloys have also been employed to measure breast cancer cells using the MUC-1 aptamer linked with the electroactive label thionine [34] or kanamycin with [Fe(CN)6]3−/4<sup>−</sup> [35]. The ability of aptamers to hybridize with other oligonucleotides was employed to create molecular gates over the pores in nanoporous gold surfaces. The gate, created with an aptamer highly specific for the avian influenza viruses (AIV) H5N1 hybridized to oligos linked to the nanoporous gold surface, was closed in the absence of AIV H5N1 but open when the virus bound and released the aptamer. The open pores allowed the entry of substrate and cofactor for lactate dehydrogenase, layered on a glassy electrode below the nanoporous gold. Cyclic voltammetry was used to detect the gold-catalyzed

oxidation of the NADH produced as a result of LDH activity [34].

Nanoporous anodized aluminum oxide surfaces have more recently been used for providing a nanoporous surface through which electron movement can be controlled by aptamer-analyte binding. In these aptasensors, the aptamers are attached to a gold surface, which is provided by 2 nm gold nanoparticles [36] or by a surface coating created by sputtering [37]. The structural change in the aptamer due to binding of the analyte reduces access of [Fe(CN)6] 3−/4<sup>−</sup> to the gold surface [36], which can be measured by EIS. Even in the absence of a redox probe, a good EIS signal can be obtained due to a combination of steric hindrance and change in electrical conductance around the pores resulting from the structural changes that occur in the highly negatively charged aptamers upon binding their targets [37].

Another type of biosensor that utilizes aptamers as bio-recognition elements is the optical sensor, for which fluorescent and colorimetric assays are the two widely used formats. In general, fluorescent detection is preferred due to its suitability for realtime detection and because there are many available labeling options as fluorophores

and quenchers, which can easily be incorporated during aptamer synthesis.

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

aptamer-functionalized aptasensor [30].

#### *Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

*Recent Advances in Analytical Chemistry*

with a detection limit of 16.6 pM [25].

target thrombin with the aptamer.

transfer and thus increases the signal [26].

In addition to their innate structural changes on binding their target molecules, other structural constraints can be applied to aptamers that result in signals for detection by electrochemical approaches. The most commonly used additional constraint is an oligonucleotide (either connected with the aptamer or separate) that is complementary to part of the aptamer and, upon hybridizing with the aptamer, constrains its structure to an inactive form. For example, a biotin-tagged DNA aptamer for zeatin was hybridized with a complimentary "assist DNA" to form a Y-type DNA structure. Avidin-modified alkaline phosphatase (ALP) was attached to this structure with two biotins at the terminals of DNA aptamer. In the presence of zeatin, this complex was disrupted which leads to a decrease in the oxidation signal from p-nitrophenol (PNP) produced by the catalytic effect of ALP. From this, zeatin concentration in the range of 50 pM–50 nM was selectively measured

Redox-active methylene blue (MB) has been used as an aptamer label and electrotransfer communication agent with the electrode. Methylene blue enables the detection of changes in aptamer conformation upon target binding. For example, an MB-labeled TA was used to construct an aptasensor by its immobilization on an electrode. The flexible conformation of the aptamer enabled the electrotransfer from MB to the electrode. The structural change upon analyte binding shielded MB in a "signal-off" mode. However, this mode is a disadvantage for diagnostics because the amperometric response decreases as a result of the association of the

Several approaches have been taken to develop aptasensors that operate in a "signal-on" mode. As an example, the TA was modified with an electroactive ferrocene group as the redox label at one end and a thiol group at the other end. The electrical contact of the electrode with the ferrocene label was affected by the long, flexible aptamer chain. Thrombin binding stabilizes the aptamer's G-quadruplex conformation, which brings the ferrocene group closer to the electrode. This close proximity enables electron transfer between the electro-active ferrocene units and the electrode, thus producing a positive signal in the presence of thrombin. A similar approach to creating signal-on electrochemical aptasensors utilized the conformational change in the cocaine aptamer that occurs on binding its target. In the absence of the target, the aptamer on the solid surface stays in a partially folded form as a three-way junction. Cocaine binding decreases the distance for electron

Demirkol et al. generated an electrochemical aptasensor to detect *E. coli* O157:H7. The electrode surfaces were modified by cysteamine via self-assembled monolayer formation. The carboxyl-functionalized quantum dots and aptamers were conjugated to cysteamine-modified gold electrodes [27]. Ge et al. reported an affinity-mediated homogeneous electrochemical aptasensor using graphenemodified glassy carbon electrode (GCE) as the sensing platform. In this approach, the aptamer-target recognition is converted into an ultrasensitive electrochemical signal output with the aid of a novel T7 exonuclease (T7Exo)-assisted target-analog recycling amplification strategy, in which ingeniously designed methylene blue (MB)-labeled hairpin DNA reporters are digested in the presence of target and, then, converted to numerous MB-labeled long ssDNAs. The distinct difference in differential pulse voltammetry response between the designed hairpin reporters and the generated long ssDNAs on the graphene/GCE allows ultrasensitive detection of target biomolecules [28]. Lai et al. proposed a renewable electrochemical aptasensor for super sensitive Hg2+ determination [29]. The novel aptasensor, based on sulfur-nitrogen co-doped ordered mesoporous carbon (SN-OMC) and a thymine-Hg2+-thymine (T-Hg2+-T) mismatch structure, used ferrocene as signal molecules to achieve the conversion of signal to current. In the absence of Hg2+,

**124**

the thiol-modified T-rich probe 1 spontaneously formed a hairpin structure by base pairing. After hybridizing with the ferrocene-labeled probe 2 in the presence of Hg2+, the hairpin structure of probe 1 was opened due to the preferential formation of the T-Hg2+-T mismatch structure, and the ferrocene signal molecules approached the modified electrode surface. Sulfur-nitrogen co-doped ordered mesoporous carbon with high specific surface area and ample active sites acted as a signal amplification element in electrochemical sensing. The sensitive determination of Hg2+ can be actualized by analyzing the relationship between the change of oxidation current caused by ferrocene and the Hg2+ concentrations [29]. Finally, Wang et al. combined the strengths of advanced aptamer technology, DNA-based nanostructure, and portable electrochemical devices to develop a nanotetrahedron (NTH)-assisted aptasensor for direct capture and detection of hepatocellular exosomes. The oriented immobilization of aptamers significantly improved their accessibility to suspended exosomes, and the NTH-assisted aptasensor could detect exosomes with 100-fold higher sensitivity when compared to the single-stranded aptamer-functionalized aptasensor [30].

Recently, nanoporous metal surfaces have been found as good sensor platforms for aptamers. Nanoporous gold [31, 32]-based sensors have been used with the TA and ATP aptamers and a redox probe to provide the electrons to the gold surface for sensitive detection of analyte by electrochemical impedance spectroscopy (EIS). The ATP aptamer was in a split format with the second half of the aptamer covalently linked with 3,4-diaminobenzoic acid (DABA), which created the EIS signal by its oxidation at the gold interface. For an analyte that can undergo redox reactions, such as bisphenol A (BPA), this property can be used to provide a signal [33]. Other nanoporous surfaces such as graphene oxide/Au composites and porous PtFe or PtTiAl ternary alloys have also been employed to measure breast cancer cells using the MUC-1 aptamer linked with the electroactive label thionine [34] or kanamycin with [Fe(CN)6]3−/4<sup>−</sup> [35]. The ability of aptamers to hybridize with other oligonucleotides was employed to create molecular gates over the pores in nanoporous gold surfaces. The gate, created with an aptamer highly specific for the avian influenza viruses (AIV) H5N1 hybridized to oligos linked to the nanoporous gold surface, was closed in the absence of AIV H5N1 but open when the virus bound and released the aptamer. The open pores allowed the entry of substrate and cofactor for lactate dehydrogenase, layered on a glassy electrode below the nanoporous gold. Cyclic voltammetry was used to detect the gold-catalyzed oxidation of the NADH produced as a result of LDH activity [34].

Nanoporous anodized aluminum oxide surfaces have more recently been used for providing a nanoporous surface through which electron movement can be controlled by aptamer-analyte binding. In these aptasensors, the aptamers are attached to a gold surface, which is provided by 2 nm gold nanoparticles [36] or by a surface coating created by sputtering [37]. The structural change in the aptamer due to binding of the analyte reduces access of [Fe(CN)6] 3−/4<sup>−</sup> to the gold surface [36], which can be measured by EIS. Even in the absence of a redox probe, a good EIS signal can be obtained due to a combination of steric hindrance and change in electrical conductance around the pores resulting from the structural changes that occur in the highly negatively charged aptamers upon binding their targets [37].

#### **2.2 Optical aptasensors**

Another type of biosensor that utilizes aptamers as bio-recognition elements is the optical sensor, for which fluorescent and colorimetric assays are the two widely used formats. In general, fluorescent detection is preferred due to its suitability for realtime detection and because there are many available labeling options as fluorophores and quenchers, which can easily be incorporated during aptamer synthesis.

To convert aptamers into fluorescent signaling probes, several strategies have been developed. A frequently used format places an aptamer sequence in a molecular beacon-like, hairpin structure in which ends are labeled either with two fluorophores or a fluorophore and a quencher. This system utilizes Förster resonance energy transfer (FRET), which relies on the energy transfer between donor and acceptor. Upon target binding, the structure is disrupted by separating the two ends, thus leading to a fluorescence signal. In this format, the use of organic fluorescent dyes or quantum dots (QDs) improved the assay performance and could also be used to detect drug delivery in cells. Another format places a fluorophorelabeled aptamer in a duplex structure with a complementary DNA sequence labeled with a quencher. The aptamer target successfully competes with the complementary DNA resulting in departure of the complementary strand from the aptamer and an accompanying increase in the fluorescence signal [26].

In optical analysis, simultaneous detection of several analytes is readily achieved by multiplexing. In one of the earliest examples, fluorescently labeled aptamers were immobilized on a glass surface. In this system, detection of thrombin and three cancer-biomarker proteins, inosine monophosphate dehydrogenase, vascular endothelial growth factor, and basic fibroblast growth factor, was achieved by fluorescence polarization even in the presence of human serum and *E. coli* cell lysates [10]. The use of aptamer-linked beads in a microarray setting brought a further sophistication of an "electronic tongue" that consists of a fluid delivery system and a fluorescence microscope attached to a digital camera for quantification [10].

Graphene oxide-based aptasensors can also be readily multiplexed [10]. As an example, a novel label-free fluorescent approach was constructed for H1N1 detection based on graphene-oxide and strand displacement reaction, using SYBR Green I (SGI) for signal amplification [38]. Another example is an assay for detection of the pathogenic bacterium, *Pseudomonas aeruginosa*. This assay was enabled by highly specific aptamers conjugated with photoluminescent carbon dots as the fluorescent probe and graphene oxide as the quencher, and it allowed detection of as low as 9 CFU mL<sup>−</sup><sup>1</sup> *P. aeruginosa* [39]. Electrochemiluminescence is another output option for aptasensors [40].

#### **2.3 Microcantilever aptasensors**

Incorporating aptamers into microcantilever sensors offers the possibility of label-free target detection, low noise, high scalability, and small testing volumes [10]. Microcantilever-based sensing has been incorporated into several experimental chemical and biological sensing systems due to its small size, low cost, low sample volume, label-free detection, and ease of integration with microfluidic devices [41]. Highthroughput analysis is achievable via microcantilever arrays for parallel processing, although they cannot easily be extensively multiplexed. Microcantilever aptasensors can be operated in either static or dynamic mode. In a liquid environment, the static mode can be more sensitive compared to the dynamic mode. In the static mode, one side of the microcantilever is functionalized with aptamers for analyte detection. Surface stress is generated when target analyte adsorbs onto the functionalized surface. The difference in surface stress between the top and bottom surface results in microcantilever bending, which can be upward (positive) or downward (negative) depending on the type of molecular interactions involved. Displacement of the beam can be detected by using readout techniques such as optical, piezoresistive, and capacitive. The optical technique is the most popular approach because it has high resolution and linear response and produces absolute displacement measurement. Detection of proteins and small molecule analytes, with an aptamer-decorated cantilever, can be achieved with many sensing means including interferometry [42–44] and piezoresistivity [45, 46]. Further

**127**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

vibration and the limits to which they can be multiplexed.

by its aptamer from the nontarget serum proteins.

, and linear range was 0.01–50 ng.mL<sup>−</sup><sup>1</sup>

development of microcantilever devices will require solutions to their sensitivity to

Early work on acoustic aptasensors included the modification of gold-coated quartz crystals with aptamers. Target binding changes the frequency or phase shift which can be detected as a change in the input and output light. For example, the IgE DNA aptamer on a quartz crystal microbalance (QCM) format provided a

Label-free and real-time quantification of proteins were also measured by the propagation of the acoustic wave in a surface acoustic wave (SAW) biosensor, which included an array of five sensor elements to detect human α-thrombin

α-thrombin and HIV-1 Rev peptide as analytes [48]. The aptamers demonstrated a better linear response, stability, and reusability when compared with antibodies

Surface plasmon resonance (SPR) sensors, similar to QCM and SAW aptasensors, rely on a change in refractive index due to target binding. Quartz crystal microbalance and surface plasmon resonance aptasensors for detection of HIV-1 Tat protein were found to have similar high specificities with the SPR sensor having a wider linear range [49]. The SPR aptasensor for retinol binding protein-4 was found more sensitive than an ELISA [50]. In developing SPR aptasensors, combined approaches resulted in a microfluidic device with interdigitated transducer creating high-frequency acoustic waves for target separation [51]. Biotinylated-thrombin aptamers were captured by streptavidin-functionalized polystyrene, which was pumped in the microchannel after incubating with sample. In the microfluidic device, SAW exposure leads to separation of thrombin captured in the polystyrene

Gold nanoparticles (AuNPs) have also been utilized in developing SPR aptasensors. A U-shaped fiber-optic SPR biosensor was developed for the rapid detection of BPA [52]. Incubation of bare AuNPs with BPA aptamer resulted in AuNPs/ssDNA complexes which are stable in high salt. Bisphenol A binding disrupted this complex, which resulted in the aggregation of AuNPs and enhanced refractive index of the solution in the fiber-optic SPR sensor. This system had a detection limit of

Neves et al. generated two sensitive cocaine aptasensors that rely on an electromagnetic piezoelectric acoustic sensor (EMPAS) platform as the basis of ultra-high frequency with tuned signal-to-noise ratio [53]. The sensing interface consists of a S-(11-trichlorosilyl-undecanyl) benzenethiosulfonate (BTS) adlayer-coated quartz disc onto which a structure-switching cocaine aptamer was immobilized, completing the preparation of the MN4 cocaine aptamer with an apparent Kd of 45 ± 12 μM and limit of detection of 0.9 μM. The same group developed an MN6 cocaine aptasensor using an EMPAS platform that had apparent Kd of 27 ± 6 and a 0.3 μM detection

Detection of cells using SPRs has some limitations that have been creatively overcome. The first limitation includes nonselective binding that causes the refractive index changes, which can be circumvented by reference flow cells to offset this effect [55]. Second is the sensing range, which is typically around 200 nm compared with cell dimensions that are in the micron range. Using long-range SPR, the depth was increased over 800 nm, which increased the sensitivity for cell detection [56]. Another drawback is its low-throughput, which has been resolved by SPR

.

for both

of IgE [47].

or HIV-1 Rev peptide. This system had a detection limit of 75 pg.cm<sup>−</sup><sup>2</sup>

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

**2.4 Acoustic aptasensors**

detection limit of 3.3 ng.cm<sup>−</sup><sup>2</sup>

specific for IgE.

3.7 pg.mL<sup>−</sup><sup>1</sup>

limit [54].

imaging technology.

development of microcantilever devices will require solutions to their sensitivity to vibration and the limits to which they can be multiplexed.

#### **2.4 Acoustic aptasensors**

*Recent Advances in Analytical Chemistry*

output option for aptasensors [40].

**2.3 Microcantilever aptasensors**

accompanying increase in the fluorescence signal [26].

To convert aptamers into fluorescent signaling probes, several strategies have been developed. A frequently used format places an aptamer sequence in a molecular beacon-like, hairpin structure in which ends are labeled either with two fluorophores or a fluorophore and a quencher. This system utilizes Förster resonance energy transfer (FRET), which relies on the energy transfer between donor and acceptor. Upon target binding, the structure is disrupted by separating the two ends, thus leading to a fluorescence signal. In this format, the use of organic fluorescent dyes or quantum dots (QDs) improved the assay performance and could also be used to detect drug delivery in cells. Another format places a fluorophorelabeled aptamer in a duplex structure with a complementary DNA sequence labeled with a quencher. The aptamer target successfully competes with the complementary DNA resulting in departure of the complementary strand from the aptamer and an

In optical analysis, simultaneous detection of several analytes is readily achieved

by multiplexing. In one of the earliest examples, fluorescently labeled aptamers were immobilized on a glass surface. In this system, detection of thrombin and three cancer-biomarker proteins, inosine monophosphate dehydrogenase, vascular endothelial growth factor, and basic fibroblast growth factor, was achieved by fluorescence polarization even in the presence of human serum and *E. coli* cell lysates [10]. The use of aptamer-linked beads in a microarray setting brought a further sophistication of an "electronic tongue" that consists of a fluid delivery system and a fluorescence microscope attached to a digital camera for quantification [10]. Graphene oxide-based aptasensors can also be readily multiplexed [10]. As an example, a novel label-free fluorescent approach was constructed for H1N1 detection based on graphene-oxide and strand displacement reaction, using SYBR Green I (SGI) for signal amplification [38]. Another example is an assay for detection of the pathogenic bacterium, *Pseudomonas aeruginosa*. This assay was enabled by highly specific aptamers conjugated with photoluminescent carbon dots as the fluorescent probe and graphene oxide as the quencher, and it allowed detection of as low as 9 CFU mL<sup>−</sup><sup>1</sup> *P. aeruginosa* [39]. Electrochemiluminescence is another

Incorporating aptamers into microcantilever sensors offers the possibility of label-free target detection, low noise, high scalability, and small testing volumes [10]. Microcantilever-based sensing has been incorporated into several experimental chemical and biological sensing systems due to its small size, low cost, low sample volume, label-free detection, and ease of integration with microfluidic devices [41]. Highthroughput analysis is achievable via microcantilever arrays for parallel processing, although they cannot easily be extensively multiplexed. Microcantilever aptasensors can be operated in either static or dynamic mode. In a liquid environment, the static mode can be more sensitive compared to the dynamic mode. In the static mode, one side of the microcantilever is functionalized with aptamers for analyte detection. Surface stress is generated when target analyte adsorbs onto the functionalized surface. The difference in surface stress between the top and bottom surface results in microcantilever bending, which can be upward (positive) or downward (negative) depending on the type of molecular interactions involved. Displacement of the beam can be detected by using readout techniques such as optical, piezoresistive, and capacitive. The optical technique is the most popular approach because it has high resolution and linear response and produces absolute displacement measurement. Detection of proteins and small molecule analytes, with an aptamer-decorated cantilever, can be achieved with many sensing means including interferometry [42–44] and piezoresistivity [45, 46]. Further

**126**

Early work on acoustic aptasensors included the modification of gold-coated quartz crystals with aptamers. Target binding changes the frequency or phase shift which can be detected as a change in the input and output light. For example, the IgE DNA aptamer on a quartz crystal microbalance (QCM) format provided a detection limit of 3.3 ng.cm<sup>−</sup><sup>2</sup> of IgE [47].

Label-free and real-time quantification of proteins were also measured by the propagation of the acoustic wave in a surface acoustic wave (SAW) biosensor, which included an array of five sensor elements to detect human α-thrombin or HIV-1 Rev peptide. This system had a detection limit of 75 pg.cm<sup>−</sup><sup>2</sup> for both α-thrombin and HIV-1 Rev peptide as analytes [48]. The aptamers demonstrated a better linear response, stability, and reusability when compared with antibodies specific for IgE.

Surface plasmon resonance (SPR) sensors, similar to QCM and SAW aptasensors, rely on a change in refractive index due to target binding. Quartz crystal microbalance and surface plasmon resonance aptasensors for detection of HIV-1 Tat protein were found to have similar high specificities with the SPR sensor having a wider linear range [49]. The SPR aptasensor for retinol binding protein-4 was found more sensitive than an ELISA [50]. In developing SPR aptasensors, combined approaches resulted in a microfluidic device with interdigitated transducer creating high-frequency acoustic waves for target separation [51]. Biotinylated-thrombin aptamers were captured by streptavidin-functionalized polystyrene, which was pumped in the microchannel after incubating with sample. In the microfluidic device, SAW exposure leads to separation of thrombin captured in the polystyrene by its aptamer from the nontarget serum proteins.

Gold nanoparticles (AuNPs) have also been utilized in developing SPR aptasensors. A U-shaped fiber-optic SPR biosensor was developed for the rapid detection of BPA [52]. Incubation of bare AuNPs with BPA aptamer resulted in AuNPs/ssDNA complexes which are stable in high salt. Bisphenol A binding disrupted this complex, which resulted in the aggregation of AuNPs and enhanced refractive index of the solution in the fiber-optic SPR sensor. This system had a detection limit of 3.7 pg.mL<sup>−</sup><sup>1</sup> , and linear range was 0.01–50 ng.mL<sup>−</sup><sup>1</sup> .

Neves et al. generated two sensitive cocaine aptasensors that rely on an electromagnetic piezoelectric acoustic sensor (EMPAS) platform as the basis of ultra-high frequency with tuned signal-to-noise ratio [53]. The sensing interface consists of a S-(11-trichlorosilyl-undecanyl) benzenethiosulfonate (BTS) adlayer-coated quartz disc onto which a structure-switching cocaine aptamer was immobilized, completing the preparation of the MN4 cocaine aptamer with an apparent Kd of 45 ± 12 μM and limit of detection of 0.9 μM. The same group developed an MN6 cocaine aptasensor using an EMPAS platform that had apparent Kd of 27 ± 6 and a 0.3 μM detection limit [54].

Detection of cells using SPRs has some limitations that have been creatively overcome. The first limitation includes nonselective binding that causes the refractive index changes, which can be circumvented by reference flow cells to offset this effect [55]. Second is the sensing range, which is typically around 200 nm compared with cell dimensions that are in the micron range. Using long-range SPR, the depth was increased over 800 nm, which increased the sensitivity for cell detection [56]. Another drawback is its low-throughput, which has been resolved by SPR imaging technology.

#### **3. Clinical perspective**

As discussed throughout this chapter, aptamers can be evolved to have high affinity and specificity for a range of target molecules that includes small organics, peptides, protein, sugar, viruses, bacteria, parasites, live cell, and tissue (**Tables 2** and **3**). This characteristic paves the way for aptamers to have applications in various disciplines including sensing, medicine, pharmacology, and microbiology. Aptamer-based sensors have great promise as effective tools in the areas of diagnostics and therapeutics for clinical use [164, 165].

#### **3.1 Clinical diagnostics**

In clinical practice, the quantification of single biomarkers is frequently not sufficient to support a confident diagnosis. Thus, multiple analyses are required for each diagnosis, many of which might rely on antibodies, the current workhorses of the diagnostic world. Although many antibodies are highly sensitive and specific for their antigen targets, they often suffer from batch-to-batch variation. ELISA assays, which are the main diagnostic platform for antibodies, have been improved with protocols that increase their efficiency and the specificity of their output. However, ELISA assays cannot be readily multiplexed to measure simultaneously the many biomarkers required for a confident diagnosis. A strength of aptamer biosensors is their ability to be multiplexed. Another strength is the range of technologies that can be applied to produce operating aptasensors [166–168]. With these strengths to drive it, aptasensor technology is one of the fastest growing biotechnology areas in diagnostics with an expectation of reaching about \$250 million by 2020 [169, 170].

Aptamers can provide new opportunities for medical diagnostics beyond what is available with antibodies [18, 171]. For example, aptamers can be selected against non-immunogenic and toxic targets, to which antibodies cannot be elicited. These short, single-stranded oligonucleotides can be synthesized via simple chemical synthesis, making them easier and less costly to produce than antibodies [172]. When synthesized in cells containing DNAs encoding RNA aptamers, they can fold appropriately and recognize intracellular targets [173–175].

A limited number of aptasensors are in the pipeline to be used in the areas such as biomarker and microorganism detection and cancer clinical testing. The available aptasensors include (1) OTA-Sense for detection of Ochratoxin A (OTA), a toxin produced by fungi [165, 176]; (2) AflaSense for detection of aflatoxins [95, 177–179]; (3) AptoCyto for flow cytometry applications [165]; (4) AptoPrep as a kit including conjugated aptamers specific to CD-31, EGFR, HGFR, and ICAM-2 [165]; (5) SOMAscan as a platform with the ability to detect >1300 proteins from small volumes [180–184]; (6) an aptamer-based proteomics technology developed by Jung et al. for detecting non-small cell lung cancer [165]; and (7) OLIGOBIND for measuring the thrombin level in blood [185].

Highly sensitive tests are required to specifically detect cancer cells in body fluids over all others. Success in this effort requires the identification of biomarkers that are found only on tumor cells. Some aptamers have been identified that might be applied to detecting tumor cells in the blood. For example, cancer cells and normal cells have been distinguished by using electrochemical sensors, a SERS active bimetallic core-satellite nanostructure, porphyrin-based covalent organic framework based aptasensor [186], and a deterministic lateral displacement (DLD) pattern-based aptamer-tailed octopus chip [187]. Recently, some aptasensors have been tested in cancer studies. Prostate-specific antigen (PSA), mucin 1 (MUC1), PDGF-BB, and vascular endothelial growth factor (VEGF) are detected as cancer biomarkers in cancer cell lines [165, 188].

**129**

*L.* 

*monocytogenes*

*Aptamers for Diagnostics with Applications for Infectious Diseases*

**Organism Target Aptamer Backbone Binding affinity (Kd) Reference**

*M. tb* H37Rv CE protein CE24 DNA 0.375 μM [58] CE protein CE15 DNA 0.16 μM *M. tb* CE protein CSIR 2.11 DNA [59]

EsxG protein G78 RNA 78.85 ± 9.40 nM

Aptamers 33 and 45

ManLAM T9 DNA 668 ± 59 nM [57]

MPT64 MPT64-A1 DNA [60, 61] EsxG protein G43 RNA 8.04 ± 1.90 nM [62]

DNA [65, 66]

recombinant Protein A and 84 ± 5 nM for the native Protein A

DNA [86]

[78]

S25 RNA [72]

Whole bacterium MA1 DNA 12.02 nM [63] Whole bacterium Aptamer 1 DNA 37 ± 4 nM [64]

OmpC protein I-2 RNA 20 nM [67] Whole bacterium C4 DNA [68] Whole bacterium ST2P DNA 6.33 ± 0.58 nM [69] Whole bacterium SAL 26 DNA 123 ± 23 nM [70]

Whole bacterium Apt22 DNA 47 ± 3 nM [71]

Whole bacterium crn1 DNA 0.971 μM [73]

S. Endotoxin C1 C10 DNA 65.14 ± 11.64 nM.L<sup>−</sup><sup>1</sup> [75] Alpha toxin R12.06 DNA 93.7 ± 7.0 nM [76] Peptidoglycan Antibac1 DNA 0.415 ± 0.047 μM [77]

Whole bacterium SA20 DNA 70.68 ± 39.22 nM [79, 80]

Whole bacterium SA17 DNA 35 nM [81]

Internalin A A8 DNA [82] Listeriolysin O LLO-3 DNA [83] Whole bacterium Lbi-17 DNA [84] Whole bacterium LMCA2 DNA 2.01x10<sup>−</sup>12 M [85]

Whole bacterium crn2 DNA 0.309 μM *S. aureus* S. Endotoxin B APTSEB1 DNA [74]

> Peptidoglycan Antibac2 DNA 1.261 ± 0.280 μM Protein A PA#2/8 DNA 172 ± 14 nM for the

Whole bacterium SA23 DNA 61.50 ± 22.43 nM Whole bacterium SA31 DNA 82.86 ± 33.20 nM Whole bacterium SA34 DNA 72.42 ± 35.23 nM Whole bacterium SA43 DNA 210.70 ± 135.91 nM

Whole bacterium SA61 DNA 129 nM

Whole bacterium LMCA26 DNA 1.56x10<sup>−</sup>10 M

*E. coli* 0158 Whole bacterium AM-6 DNA 107.6 ± 67.8 pmol [87] *E. coli* K88 Whole bacterium Apt B12 DNA 15 ± 4 nM [88]

E-12, E-16 to E-19

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

*S. typhimurium* Outer membrane

*S*. *enteritidis* Mixtures of

proteins

10 strains of *S. enteritidis*

*E. coli* 0157 LPS E-5, E-11,

*M. tb* Beijing strain

*Salmonella* Paratyphi A


#### *Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

*Recent Advances in Analytical Chemistry*

As discussed throughout this chapter, aptamers can be evolved to have high affinity and specificity for a range of target molecules that includes small organics, peptides, protein, sugar, viruses, bacteria, parasites, live cell, and tissue (**Tables 2** and **3**). This characteristic paves the way for aptamers to have applications in various disciplines including sensing, medicine, pharmacology, and microbiology. Aptamer-based sensors have great promise as effective tools in the areas of diagnostics and therapeu-

In clinical practice, the quantification of single biomarkers is frequently not sufficient to support a confident diagnosis. Thus, multiple analyses are required for each diagnosis, many of which might rely on antibodies, the current workhorses of the diagnostic world. Although many antibodies are highly sensitive and specific for their antigen targets, they often suffer from batch-to-batch variation. ELISA assays, which are the main diagnostic platform for antibodies, have been improved with protocols that increase their efficiency and the specificity of their output. However, ELISA assays cannot be readily multiplexed to measure simultaneously the many biomarkers required for a confident diagnosis. A strength of aptamer biosensors is their ability to be multiplexed. Another strength is the range of technologies that can be applied to produce operating aptasensors [166–168]. With these strengths to drive it, aptasensor technology is one of the fastest growing biotechnology areas in diagnostics with an expectation of reaching about \$250 million by 2020 [169, 170]. Aptamers can provide new opportunities for medical diagnostics beyond what is available with antibodies [18, 171]. For example, aptamers can be selected against non-immunogenic and toxic targets, to which antibodies cannot be elicited. These short, single-stranded oligonucleotides can be synthesized via simple chemical synthesis, making them easier and less costly to produce than antibodies [172]. When synthesized in cells containing DNAs encoding RNA aptamers, they can fold

A limited number of aptasensors are in the pipeline to be used in the areas such as biomarker and microorganism detection and cancer clinical testing. The available aptasensors include (1) OTA-Sense for detection of Ochratoxin A (OTA), a toxin produced by fungi [165, 176]; (2) AflaSense for detection of aflatoxins [95, 177–179]; (3) AptoCyto for flow cytometry applications [165]; (4) AptoPrep as a kit including conjugated aptamers specific to CD-31, EGFR, HGFR, and ICAM-2 [165]; (5) SOMAscan as a platform with the ability to detect >1300 proteins from small volumes [180–184]; (6) an aptamer-based proteomics technology developed by Jung et al. for detecting non-small cell lung cancer [165]; and (7) OLIGOBIND for

Highly sensitive tests are required to specifically detect cancer cells in body fluids over all others. Success in this effort requires the identification of biomarkers that are found only on tumor cells. Some aptamers have been identified that might be applied to detecting tumor cells in the blood. For example, cancer cells and normal cells have been distinguished by using electrochemical sensors, a SERS active bimetallic core-satellite nanostructure, porphyrin-based covalent organic framework based aptasensor [186], and a deterministic lateral displacement (DLD) pattern-based aptamer-tailed octopus chip [187]. Recently, some aptasensors have been tested in cancer studies. Prostate-specific antigen (PSA), mucin 1 (MUC1), PDGF-BB, and vascular endothelial growth factor (VEGF) are detected as cancer biomarkers in

appropriately and recognize intracellular targets [173–175].

measuring the thrombin level in blood [185].

**3. Clinical perspective**

tics for clinical use [164, 165].

**3.1 Clinical diagnostics**

**128**

cancer cell lines [165, 188].


#### **Table 2.**

*Aptamers selected against bacteria.*


**131**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

Whole virus IF22 and

Gp120 BclON-

Gp120 F-thio-

5'-UTR of HIV-1 genome

> TAR RNA element

Nucleocapsid protein

Truncated protease domain of NS3 protein

Helicase domain of NS3

IRES domains III-IV

IRES domain IIIf and IV

IF23

mut

BclON

RT FA1 FANA

**Organism Target Aptamer Backbone Binding affinity (Kd) Reference**

HBV Surface antigen HBs-A22 RNA [119] HPV 16 E7 protein G5α3N.4 RNA 1.9 μM [120] HIV-1 Gp120 B40 RNA 21 ± 2 nM [121] Gp120 B40t77 RNA 31 ± 2 nM

HA A9 DNA 46.23 ± 5.46 nM [116]

HA B4 DNA 7.38 ± 1.09 nM [117]

Gp120 A-1 RNA 52 nM [122]

RT 1.1RNA RNA 5 nM [124] RT RT1t49 DNA 1 nM [125] RT 4.20 DNA 180 ± 70 pM [126] RT R12–2 DNA 70 nM [127] RT 37NT DNA 660 pM [128]

Integrase T30695 DNA 0.5 ± 0.2 μM [132, 133] Integrase 93del DNA [56, 134, 135]

8–6 RNA 1.4x10<sup>−</sup><sup>9</sup>

Gag protein DP6–22 RNA 100 ± 3.4 nM [137] Rev protein RBE(apt) RNA [138] Integrase S3R3 RNA 47 ± 3 nM [139]

HCV NS3 protein G6–16 RNA 238 nM [140]

aptamer

DNA 86 ± 17 nM

RNApt16 RNA 280 ± 60 nM [130]

IV04 DNA 20 nM [131]

G9-I RNA 10 nM [141]

G5 RNA 25 nM [142]

3–07 RNA 9 nM [143]

HH-11 RNA [146]

IRES AP50 RNA 5 nM [144, 145]

NS5B 27v DNA 132.3 ± 20 nM [147, 148] NS5B r10/43 RNA 1.3 ± 0.3 nM [149]

NS5B R-F t2 RNA 2.62 ± 0.90 nM [85, 150]

NS5B r10/47 RNA 23.5 ± 6.7 nM

DNA [118]

DNA 143 ± 79 nM [123]

Low pM range [129]

M [136]

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

Influenza A virus (H9N2)

Influenza A virus (H9N2)

Influenza A virus (H5N1) and (H5N8)


#### *Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

*Recent Advances in Analytical Chemistry*

*M. tb* Acetohydroxyacid

*Aptamers selected against bacteria.*

synthase

Acetohydroxyacid synthase

*E. coli* KCTC 2571

**Organism Target Aptamer Backbone Binding affinity (Kd) Reference** HIV-1 Tat RNATat RNA 120 ± 13 pM [49, 100, 101] HCV E2 protein ZE2 DNA 1.05 ± 1 nM [102]

**Organism Target Aptamer Backbone Binding affinity (Kd) Reference**

Whole bacterium E2 DNA 25.2 nM Whole bacterium E10 DNA 14.2 nM Whole bacterium E12 DNA 16.8 nM *E. coli* DH5α Whole cell Ec3(31) RNA 225 nM [90]

*M. tb* H37Rv Whole bacterium NK2 DNA [92]

BCG ManLAM BM2 DNA 8.59 ± 1 .23 nM [94]

*S. typhi* Type IVB pili S-PS8.4 RNA 8.56 nM [96, 97] *S. aureus* SEA S3 DNA 36.93 ± 7.29 nM [98]

α-toxin AT-36 DNA

Whole bacterium E1 DNA 12.4 nM [35, 89]

Whole cell 8.28A DNA 27.4 ± 18.7 nM [91]

ManLAM ZXL1 DNA 436.3 ± 37.84 nM [93]

Mtb-Apt6 DNA 0.210 ± 0.05 μM

α-toxin AT-33 DNA [99]

Mtb-Apt1 DNA 1.06 ± 0.10 μM [95]

Core protein 9–15 RNA 224 nM

Core protein 9–14 RNA 142 nM [103]

Core protein C4 DNA [104, 105]

HA A10 DNA [109]

HA HAS15–5 RNA [111]

HA D-26 RNA 67 fM [112]

HA HA68 DNA 7.1 nM [113]

HA1 subunit ApI DNA 64.76 ± 18.24 nM [115]

HA1 subunit ApII DNA 69.06 ± 12.34 nM

HA1 subunit ApIII DNA 50.32 ± 14.07 nM

8-3 RNA 170 fM [114]

HA(101–257) C7 DNA [110]

HA(91–261) A22 DNA [106] HA Clone B RNA 200 pM [107] Whole virus P30-10-16 RNA 188 pM [108]

**130**

Influenza A virus (H3N2)

**Table 2.**

Influenza A virus (H5N1)

Influenza A virus (H9N2)

Influenza A virus (H5N1)

Influenza A virus (H1N1)

Influenza A virus (H3N2)

Influenza A virus (H5N1) and (H7N7)

Influenza A virus

Influenza A virus

Influenza A virus

HAs from H5N1 and H7N7


#### **Table 3.**

*Aptamers selected against viruses.*

Many conventional diagnostic technologies for detecting virus and bacteria, including serologic-, nucleic acid-, and culture-based tests, are either timeconsuming or expensive on account of the need for sophisticated equipment [188]. For example, the gold standard for laboratory diagnosis of acute viral infections is isolation and characterization of the virus or bacterium. Isolation and long replication times for some viruses and bacterial strains can delay confirmation of the initial diagnosis for more than a week. The most commonly used alternative method is the ELISA. However, cross-reactive antibodies against viruses, particularly when they are part of the same virus family, may confound the results of serologic tests and may lead to misinterpretation during the epidemiologic assessment in regions of the world where they are co-endemic [189]. For instance, among the flaviviruses, serological cross-reactivity between Zika virus and dengue virus confounds diagnosis of Zika virus infections in pregnant woman in regions where Dengue virus is also endemic [190]. Additionally, ELISA-detecting antibodies (IgG and IgM) that were produced against the virus do not identify the active infection or the virus particles. Because they can interact with different regions of the protein compared with antibodies, aptamers might be capable of distinguishing viruses that cannot be distinguished serologically [162]. Aptamers that have been reported to specifically bind flaviviruses and their protein products including Ebola [162], Zika [163], and dengue virus [160] should be tested for their abilities to distinguish these viruses.

The abilities to detect, identify, and quantify microbes and viruses and to identify virally infected cells are essential for their early diagnosis. An increasing number of aptamers have been isolated that bind specific microbes such as *Escherichia coli*, *Bacillus thuringiensis*, *Campylobacter jejuni*, *and Campylobacter coli* [191], various salmonella species, including *S. enteritidis* [72] and *S. enterica* [65], and staphylococcus species including *S. aureus* [79], *S. typhimurium* [67], and *S.* 

**133**

symptoms [202].

**4. Future perspective**

45 billion dollars global diagnostics market.

*Aptamers for Diagnostics with Applications for Infectious Diseases*

hepatitis C virus (HCV) [188], among others (**Table 3**).

stubborn diagnostic problems. Here we discuss some examples.

because of the poor bacillary count [195–197].

*enteritidis* [192] (**Table 2**). In addition to the aptamers recognizing flaviviruses discussed in the previous paragraph, there are also aptamers that bind HIV-1 and

Aptasensors that have been developed using a number of the aptamers just mentioned hold the promise of prompt management of infections with a decreasing incidence of morbidity. Another possible application of aptasensors is in vaccine development. The costs and extended time associated with the assessment of vaccine concentrations by ELISA might be overcome by the application of aptasensors [193].

Application of aptamer technology in the clinic has the potential of solving some

Tuberculosis (TB) is caused by *Mycobacterium tuberculosis* and is one of the top ten causes of death worldwide [194]. The incidence of childhood TB is reported as a half a million cases with 74,000 deaths annually by the World Health Organization [195]. The most commonly used diagnostic tool for tuberculosis is the TB skin test. However, a false-positive test result in people vaccinated with the bacillus Calmette-Guerin (BCG) vaccine can be a confounding factor for diagnosis. Thus, the distinction of infection from disease, particularly in children, is still unclear. Additionally, microbiologic confirmation of bacteria in body fluids in childhood is difficult

Cytomegalovirus (CMV) causes life-threatening infections in patients with solid organ transplantation, hematopoietic stem cell transplantation, and AIDS. Cytomegalovirus causes acute and latent infections and reactivates in immunosuppressed patients. Isolation and infection control procedures as well as proper management of VHFs commonly depend on an accurate diagnosis [198]. Current diagnostic tests targeting CMV DNA and CMV antigens are insufficient for discriminating acute and latent infections and detecting organ involvement. As a result, the results of these tests are frequently misinterpreted [199–201]. Viral hemorrhagic fevers (VHFs) are caused by a couple of viruses including *Arenaviridae*, *Bunyaviridae*, *Filoviridae*, and *Flaviviridae*. Fulminant and fatal disease processes are the common features of the VHFs and diagnosing and distinguishing of VHF from other tropical diseases may be problematic because of the indiscriminatory

An accurate and reliable diagnosis of these and other infections will provide for appropriate management and will decrease morbidity and mortality. Thus, development of fast microorganism-focused tests will provide rapid accurate diagnosis of infection and organ involvements. It seems inevitable that, in the near future, many aptamer-based methods/tools will provide for early diagnosis that will enable rapid initiation of optimal treatment regimens for viral and bacterial diseases.

First identified in 1890 [203], antibodies and their means of interaction with their antigens were already being extensively studied in the early twentieth century, and their structures were reported in the 1960s by Gerald Edelman [204]. Continuing studies of antibodies and the means of eliciting them have resulted in a detailed understanding of how they interact with their antigens. This knowledge combined with an expansive array of available antibodies motivates scientists to incorporate them into new diagnostic tools. Thus, antibody use dominates the

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

**3.2 Future directions in clinics**

*enteritidis* [192] (**Table 2**). In addition to the aptamers recognizing flaviviruses discussed in the previous paragraph, there are also aptamers that bind HIV-1 and hepatitis C virus (HCV) [188], among others (**Table 3**).

Aptasensors that have been developed using a number of the aptamers just mentioned hold the promise of prompt management of infections with a decreasing incidence of morbidity. Another possible application of aptasensors is in vaccine development. The costs and extended time associated with the assessment of vaccine concentrations by ELISA might be overcome by the application of aptasensors [193].

#### **3.2 Future directions in clinics**

*Recent Advances in Analytical Chemistry*

HBV Truncated P

DENV-2 Envelope

*Aptamers selected against viruses.*

Glycosylated HA

Residues in the N-terminal of the PAN of the influenza A virus polymerase

protein

protein domain III

Influenza A virus (H5N2)

Influenza A virus (H1N1, H5N1, H7N7 and H7N9)

**Table 3.**

Many conventional diagnostic technologies for detecting virus and bacteria,

**Organism Target Aptamer Backbone Binding affinity (Kd) Reference**

HPV 16 E7 protein A2 RNA 107 nM [156, 157]

SARS-CoV Helicase NG8 DNA 5 nM [159]

RABV Glycoprotein GE54 DNA 307 nM [161] EBOV EBOV sGP 39SGP1A RNA 27 nM [162] Zika NS1 protein Clone 2 DNA 24 pM [163] NS1 protein Clone 10 DNA 134 nM

HA12–16 RNA [151]

PAN-2 DNA 247 ± 11 nM [152]

S9 RNA [153]

S15 DNA 200 nM [160]

Core protein Apt.No.28 DNA [154] Capsid AO-01 DNA 180 ± 82 nM [155]

E6 protein F2 RNA [158]

consuming or expensive on account of the need for sophisticated equipment [188]. For example, the gold standard for laboratory diagnosis of acute viral infections is isolation and characterization of the virus or bacterium. Isolation and long replication times for some viruses and bacterial strains can delay confirmation of the initial diagnosis for more than a week. The most commonly used alternative method is the ELISA. However, cross-reactive antibodies against viruses, particularly when they are part of the same virus family, may confound the results of serologic tests and may lead to misinterpretation during the epidemiologic assessment in regions of the world where they are co-endemic [189]. For instance, among the flaviviruses, serological cross-reactivity between Zika virus and dengue virus confounds diagnosis of Zika virus infections in pregnant woman in regions where Dengue virus is also endemic [190]. Additionally, ELISA-detecting antibodies (IgG and IgM) that were produced against the virus do not identify the active infection or the virus particles. Because they can interact with different regions of the protein compared with antibodies, aptamers might be capable of distinguishing viruses that cannot be distinguished serologically [162]. Aptamers that have been reported to specifically bind flaviviruses and their protein products including Ebola [162], Zika [163], and dengue virus [160] should be tested for their abilities to distinguish these viruses. The abilities to detect, identify, and quantify microbes and viruses and to identify virally infected cells are essential for their early diagnosis. An increasing number of aptamers have been isolated that bind specific microbes such as *Escherichia coli*, *Bacillus thuringiensis*, *Campylobacter jejuni*, *and Campylobacter coli* [191], various salmonella species, including *S. enteritidis* [72] and *S. enterica* [65], and staphylococcus species including *S. aureus* [79], *S. typhimurium* [67], and *S.* 

including serologic-, nucleic acid-, and culture-based tests, are either time-

**132**

Application of aptamer technology in the clinic has the potential of solving some stubborn diagnostic problems. Here we discuss some examples.

Tuberculosis (TB) is caused by *Mycobacterium tuberculosis* and is one of the top ten causes of death worldwide [194]. The incidence of childhood TB is reported as a half a million cases with 74,000 deaths annually by the World Health Organization [195]. The most commonly used diagnostic tool for tuberculosis is the TB skin test. However, a false-positive test result in people vaccinated with the bacillus Calmette-Guerin (BCG) vaccine can be a confounding factor for diagnosis. Thus, the distinction of infection from disease, particularly in children, is still unclear. Additionally, microbiologic confirmation of bacteria in body fluids in childhood is difficult because of the poor bacillary count [195–197].

Cytomegalovirus (CMV) causes life-threatening infections in patients with solid organ transplantation, hematopoietic stem cell transplantation, and AIDS. Cytomegalovirus causes acute and latent infections and reactivates in immunosuppressed patients. Isolation and infection control procedures as well as proper management of VHFs commonly depend on an accurate diagnosis [198]. Current diagnostic tests targeting CMV DNA and CMV antigens are insufficient for discriminating acute and latent infections and detecting organ involvement. As a result, the results of these tests are frequently misinterpreted [199–201]. Viral hemorrhagic fevers (VHFs) are caused by a couple of viruses including *Arenaviridae*, *Bunyaviridae*, *Filoviridae*, and *Flaviviridae*. Fulminant and fatal disease processes are the common features of the VHFs and diagnosing and distinguishing of VHF from other tropical diseases may be problematic because of the indiscriminatory symptoms [202].

An accurate and reliable diagnosis of these and other infections will provide for appropriate management and will decrease morbidity and mortality. Thus, development of fast microorganism-focused tests will provide rapid accurate diagnosis of infection and organ involvements. It seems inevitable that, in the near future, many aptamer-based methods/tools will provide for early diagnosis that will enable rapid initiation of optimal treatment regimens for viral and bacterial diseases.

#### **4. Future perspective**

First identified in 1890 [203], antibodies and their means of interaction with their antigens were already being extensively studied in the early twentieth century, and their structures were reported in the 1960s by Gerald Edelman [204]. Continuing studies of antibodies and the means of eliciting them have resulted in a detailed understanding of how they interact with their antigens. This knowledge combined with an expansive array of available antibodies motivates scientists to incorporate them into new diagnostic tools. Thus, antibody use dominates the 45 billion dollars global diagnostics market.

The more recently discovered aptamers are generally compared with antibodies due to their functional similarity. Since the discovery of aptamers in the 1990s, over a thousand studies have been conducted on applications of aptamers for diagnostics. Aptamers that specifically target biomarkers and bacterial or viral virulence factors such as surface glycoproteins or secreted proteins have been generated. These studies have demonstrated the range of targets that can be recognized by aptamers and the number of sensor platforms into which aptamers can be incorporated, many of which have been discussed in this chapter. However, the more structurally flexible aptamers are not as readily plugged into standard diagnostic assays as antibodies. In this burgeoning and yet immature field of aptasensors, there is still much to be learned about how to control aptamer behavior.

More systematic studies are needed to optimize selection methods, and more aptamers need to be characterized structurally. The biological matrix in which the analyte will be measured in the final application platform should be considered at the beginning of the selection so as to use buffer and ionic compositions during SELEX that resemble the target matrix. Maturation of aptamers to increase specificity for their target analyte in the appropriate matrix and for effective performance in the chosen reporter platform is also extremely important.

Aptamers offer the allure of easier production, ease of chemical modification, smaller size, reusability, stability even at high temperatures, low cost, and a long shelf life. A variety of chemical modifications further enhance aptamer stability. A significant advantage over antibody-based assays is that aptamers can be reused for many cycles without losing potency with the analyte being removed between each cycle by heating or other means. These features hold promise for the continued incorporation of aptamers into various sensor platforms and for the further development and eventual commercial application of aptasensors for diagnostics.

#### **Acknowledgements**

Authors are thankful to the administrative staff members at IntechOpen for their invaluable help.

**135**

**Author details**

and Marit Nilsen-Hamilton3

Muslum Ilgu1

Turkey

Turkey

provided the original work is properly cited.

Iowa State University, Ames, IA, USA

\*Address all correspondence to: ilgu@metu.edu.tr

\*, Rezzan Fazlioglu1

*Aptamers for Diagnostics with Applications for Infectious Diseases*

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Meric Ozturk1

1 Department of Biological Sciences, Middle East Technical University, Ankara,

2 Department of Pediatric Infectious Diseases, Hacettepe University, Ankara,

3 Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology,

, Yasemin Ozsurekci<sup>2</sup>

#### **Conflict of interest**

MNH is the owner of Aptalogic Inc. located in Ames, IA, USA.

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

#### **Author details**

*Recent Advances in Analytical Chemistry*

aptamer behavior.

aptasensors for diagnostics.

**Acknowledgements**

their invaluable help.

**Conflict of interest**

The more recently discovered aptamers are generally compared with antibodies due to their functional similarity. Since the discovery of aptamers in the 1990s, over a thousand studies have been conducted on applications of aptamers for diagnostics. Aptamers that specifically target biomarkers and bacterial or viral virulence factors such as surface glycoproteins or secreted proteins have been generated. These studies have demonstrated the range of targets that can be recognized by aptamers and the number of sensor platforms into which aptamers can be incorporated, many of which have been discussed in this chapter. However, the more structurally flexible aptamers are not as readily plugged into standard diagnostic assays as antibodies. In this burgeoning and yet immature field of aptasensors, there is still much to be learned about how to control

More systematic studies are needed to optimize selection methods, and more aptamers need to be characterized structurally. The biological matrix in which the analyte will be measured in the final application platform should be considered at the beginning of the selection so as to use buffer and ionic compositions during SELEX that resemble the target matrix. Maturation of aptamers to increase specificity for their target analyte in the appropriate matrix and for effective performance

Aptamers offer the allure of easier production, ease of chemical modification, smaller size, reusability, stability even at high temperatures, low cost, and a long shelf life. A variety of chemical modifications further enhance aptamer stability. A significant advantage over antibody-based assays is that aptamers can be reused for many cycles without losing potency with the analyte being removed between each cycle by heating or other means. These features hold promise for the continued incorporation of aptamers into various sensor platforms and for the further development and eventual commercial application of

Authors are thankful to the administrative staff members at IntechOpen for

MNH is the owner of Aptalogic Inc. located in Ames, IA, USA.

in the chosen reporter platform is also extremely important.

**134**

Muslum Ilgu1 \*, Rezzan Fazlioglu1 , Meric Ozturk1 , Yasemin Ozsurekci<sup>2</sup> and Marit Nilsen-Hamilton3

1 Department of Biological Sciences, Middle East Technical University, Ankara, Turkey

2 Department of Pediatric Infectious Diseases, Hacettepe University, Ankara, Turkey

3 Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA

\*Address all correspondence to: ilgu@metu.edu.tr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Dahm R. Friedrich Miescher and the discovery of DNA. Developmental Biology. 2005;**278**(2):274-288. DOI: 10.1016/j.ydbio.2004.11.028

[2] Lipfert J, Doniach S, Das R, Herschlag D. Understanding nucleic acid-ion interactions. Annual Review of Biochemistry. 2014;**83**:813-841. DOI: 10.1146/annurev-biochem-060409-092720

[3] Song KM, Lee S, Ban C. Aptamers and their biological applications. Sensors. 2012;**12**(1):612-631. DOI: 10.3390/s120100612

[4] Tuerk C, Gold L. Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase. Science. 1990;**249**(4968): 505-510. DOI: 10.1126/science.2200121

[5] Ellington AD, Szostak JW. In vitro selection of RNA molecules that bind specific ligands. Nature. 1990;**346**: 818-822. DOI: 10.1038/346818a0

[6] Robertson DL, Joyce GF. Selection in vitro of an RNA enzyme that specifically cleaves single-stranded DNA. Nature. 1990;**344**(6265):467-468. DOI: 10.1038/344467a0

[7] Hoinka J, Zotenko E, Friedman A, Sauna ZE, Przytycka TM. Identification of sequence-structure RNA binding motifs for SELEX-derived aptamers. Bioinformatics. 2012;**28**(12):i215-223. DOI: 10.1093/bioinformatics/bts210

[8] Hoinka J, Berezhnoy A, Sauna ZE, Gilboa E, Przytycka TM. AptaCluster—A method to cluster HT-SELEX aptamer pools and lessons from its application. Lecture Notes in Computer Science. 2014;**8394**(LNBI):115-128. DOI: 10.1007/978-3-319-05269-4\_9

[9] Tombelli S, Minunni M, Mascini M. Analytical applications of aptamers.

Biosensors & Bioelectronics. 2005;**20**(12):2424-2434. DOI: 10.1016/j. bios.2004.11.006

[10] Ilgu M, Nilsen-Hamilton M. Aptamers in analytics. The Analyst. 2016;**141**(5):1551-1568. DOI: 10.1039/ c5an01824b

[11] Yu Q, Dai Z, Wu W, Zhu H, Ji L. Effects of different buffers on the construction of aptamer sensors. IOP Conference Series: Materials Science and Engineering. 2017;**274**(1):012117. DOI: 10.1088/1757-899X/274/1/012117

[12] Bruno JG, Sivils JC. Studies of DNA aptamer oligreen and picogreen fluorescence interactions in buffer and serum. Journal of Fluorescence. 2016;**26**(4):1479-1487. DOI: 10.1007/ s10895-016-1840-1

[13] Baaske P, Wienken CJ, Reineck P, Duhr S, Braun D. Optical thermophoresis for quantifying the buffer dependence of aptamer binding. Angewandte Chemie International Edition. 2010;**49**(12):2238-2241. DOI: 10.1002/anie.200903998

[14] Radom F, Jurek PM, Mazurek MP, Otlewski J, Jeleń F. Aptamers: Molecules of great potential. Biotechnology Advances. 2013;**31**(8):1260-1274. DOI: 10.1016/j.biotechadv.2013.04.007

[15] Parisien M, Major F. The MC-Fold and MC-Sym pipeline infers RNA structure from sequence data. Nature. 2008;**452**(7183):51-55. DOI: 10.1038/ nature06684

[16] Lu XJ, Bussemaker HJ, Olson WK. DSSR: An integrated software tool for dissecting the spatial structure of RNA. Nucleic Acids Research. 2015;**43**(21):e142. DOI: 10.1093/nar/gkv716

[17] Chojnowski G, Waleń T, Bujnicki JM. RNA bricks—A database of RNA 3D

**137**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

and enzymatic signal amplification. The Analyst. 2018:**143**(21):5185-5190. DOI:

[26] Song S, Wang L, Li J, Fan C, Zhao J. Aptamer-based biosensors. Trends in Analytical Chemistry. 2008;**27**(2):108- 117. DOI: 10.1016/j.trac.2007.12.004

[27] Odacı-Demirkol D, Güleç K. Electrochemical sensing and fluorescence imaging of *E. coli*

O157:H7 based on aptamer-conjugated semiconducting nanoparticles. Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi. 2018;**22**:421-426

[28] Ge L, Wang W, Sun X, Hou T, Li F. Affinity-mediated homogeneous electrochemical aptasensor on a graphene platform for ultrasensitive biomolecule detection via exonucleaseassisted target-analog recycling amplification. Analytical Chemistry. 2016;**88**(4):2212-2219. DOI: 10.1021/acs.

[29] Lai C, Liu S, Zhang C, Zeng G,

electrochemical aptasensor based on sulfur-nitrogen Co-doped ordered mesoporous carbon and thymine-Hg2+ thymine mismatch structure for Hg2+ detection. ACS Sensors. 2018;**3**(12):2566- 2573. DOI: 10.1021/acssensors.8b00926

[30] Wang S, Zhang L, Wan S, Cansiz S, Cui C, Liu Y, et al. Aptasensor with expanded nucleotide using DNA nanotetrahedra for electrochemical detection of cancerous exosomes. ACS Nano. 2017;**11**(4):3943-3949. DOI:

[31] Qiu H, Sun Y, Huang X, Qu Y. A sensitive nanoporous gold-based electrochemical aptasensor for

10.1016/j.colsurfb.2010.04.017

Aptamer-based electrochemical

thrombin detection. Colloids Surfaces B Biointerfaces. 2010;**79**(1):304-308. DOI:

[32] Kashefi-Kheyrabadi L, Mehrgardi MA.

10.1039/C8AN01356J

analchem.5b03844

Huang D, Qin L, et al. An

10.1021/acsnano.7b00373

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

motifs and their interactions. Nucleic Acids Research. 2014;**42**(Database issue): D123-D131. DOI: 10.1093/nar/gkt1084

[18] Banerjee J, Nilsen-Hamilton M. Aptamers: Multifunctional molecules for biomedical research. Journal of Molecular Medicine. 2013;**91**(12):1333- 1342. DOI: 10.1007/s00109-013-1085-2

[19] Zhou G, Latchoumanin O, Bagdesar M, Hebbard L, Duan W, Liddle C, et al. Aptamer-based therapeutic approaches to target cancer stem cells. Theranostics. 2017;**7**(16):3948-3961. DOI: 10.7150/

Condorelli G, Ungaro P, De Franciscis V. Aptamer chimeras for therapeutic delivery: The challenging perspectives. Genes (Basel). 2018;**9**(11):529. DOI:

[21] Ismail SI, Alshaer W. Therapeutic aptamers in discovery, preclinical and clinical stages. Advanced Drug Delivery Reviews. 2018;**134**:51-64. DOI: 10.1016/j.

[22] Chen M, Yu Y, Jiang F, Zhou J, Li Y, Liang C, et al. Development of cell-SELEX technology and its application in cancer diagnosis and therapy. International Journal of Molecular Sciences. 2016;**17**(12):2079. DOI:

[23] Drolet DW, Moon-McDermott L,

Biotechnology. 1996;**14**(8):1021-1025.

[24] Ikebukuro K, Kiyohara C, Sode K. Electrochemical detection of protein using a double aptamer sandwich. Analytical Letters. 2004;**37**(14):2901- 2909. DOI: 10.1081/AL-200035778

[25] Zhou Y, Yin H, Wang Y, Sui C, Wang M, Ai S. Electrochemical aptasensors for zeatin detection based on MoS2 nanosheets

Romig TS. An enzyme-linked oligonucleotide assay. Nature

DOI: 10.1038/nbt0896-1021

[20] Esposito CL, Catuogno S,

10.3390/genes9110529

addr.2018.08.006

10.3390/ijms17122079

thno.20725

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

motifs and their interactions. Nucleic Acids Research. 2014;**42**(Database issue): D123-D131. DOI: 10.1093/nar/gkt1084

[18] Banerjee J, Nilsen-Hamilton M. Aptamers: Multifunctional molecules for biomedical research. Journal of Molecular Medicine. 2013;**91**(12):1333- 1342. DOI: 10.1007/s00109-013-1085-2

[19] Zhou G, Latchoumanin O, Bagdesar M, Hebbard L, Duan W, Liddle C, et al. Aptamer-based therapeutic approaches to target cancer stem cells. Theranostics. 2017;**7**(16):3948-3961. DOI: 10.7150/ thno.20725

[20] Esposito CL, Catuogno S, Condorelli G, Ungaro P, De Franciscis V. Aptamer chimeras for therapeutic delivery: The challenging perspectives. Genes (Basel). 2018;**9**(11):529. DOI: 10.3390/genes9110529

[21] Ismail SI, Alshaer W. Therapeutic aptamers in discovery, preclinical and clinical stages. Advanced Drug Delivery Reviews. 2018;**134**:51-64. DOI: 10.1016/j. addr.2018.08.006

[22] Chen M, Yu Y, Jiang F, Zhou J, Li Y, Liang C, et al. Development of cell-SELEX technology and its application in cancer diagnosis and therapy. International Journal of Molecular Sciences. 2016;**17**(12):2079. DOI: 10.3390/ijms17122079

[23] Drolet DW, Moon-McDermott L, Romig TS. An enzyme-linked oligonucleotide assay. Nature Biotechnology. 1996;**14**(8):1021-1025. DOI: 10.1038/nbt0896-1021

[24] Ikebukuro K, Kiyohara C, Sode K. Electrochemical detection of protein using a double aptamer sandwich. Analytical Letters. 2004;**37**(14):2901- 2909. DOI: 10.1081/AL-200035778

[25] Zhou Y, Yin H, Wang Y, Sui C, Wang M, Ai S. Electrochemical aptasensors for zeatin detection based on MoS2 nanosheets and enzymatic signal amplification. The Analyst. 2018:**143**(21):5185-5190. DOI: 10.1039/C8AN01356J

[26] Song S, Wang L, Li J, Fan C, Zhao J. Aptamer-based biosensors. Trends in Analytical Chemistry. 2008;**27**(2):108- 117. DOI: 10.1016/j.trac.2007.12.004

[27] Odacı-Demirkol D, Güleç K. Electrochemical sensing and fluorescence imaging of *E. coli* O157:H7 based on aptamer-conjugated semiconducting nanoparticles. Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi. 2018;**22**:421-426

[28] Ge L, Wang W, Sun X, Hou T, Li F. Affinity-mediated homogeneous electrochemical aptasensor on a graphene platform for ultrasensitive biomolecule detection via exonucleaseassisted target-analog recycling amplification. Analytical Chemistry. 2016;**88**(4):2212-2219. DOI: 10.1021/acs. analchem.5b03844

[29] Lai C, Liu S, Zhang C, Zeng G, Huang D, Qin L, et al. An electrochemical aptasensor based on sulfur-nitrogen Co-doped ordered mesoporous carbon and thymine-Hg2+ thymine mismatch structure for Hg2+ detection. ACS Sensors. 2018;**3**(12):2566- 2573. DOI: 10.1021/acssensors.8b00926

[30] Wang S, Zhang L, Wan S, Cansiz S, Cui C, Liu Y, et al. Aptasensor with expanded nucleotide using DNA nanotetrahedra for electrochemical detection of cancerous exosomes. ACS Nano. 2017;**11**(4):3943-3949. DOI: 10.1021/acsnano.7b00373

[31] Qiu H, Sun Y, Huang X, Qu Y. A sensitive nanoporous gold-based electrochemical aptasensor for thrombin detection. Colloids Surfaces B Biointerfaces. 2010;**79**(1):304-308. DOI: 10.1016/j.colsurfb.2010.04.017

[32] Kashefi-Kheyrabadi L, Mehrgardi MA. Aptamer-based electrochemical

**136**

*Recent Advances in Analytical Chemistry*

[1] Dahm R. Friedrich Miescher and the discovery of DNA. Developmental Biology. 2005;**278**(2):274-288. DOI:

Biosensors & Bioelectronics.

[10] Ilgu M, Nilsen-Hamilton M. Aptamers in analytics. The Analyst. 2016;**141**(5):1551-1568. DOI: 10.1039/

[11] Yu Q, Dai Z, Wu W, Zhu H, Ji L. Effects of different buffers on the construction of aptamer sensors. IOP Conference Series: Materials Science and Engineering. 2017;**274**(1):012117. DOI: 10.1088/1757-899X/274/1/012117

[12] Bruno JG, Sivils JC. Studies of DNA aptamer oligreen and picogreen fluorescence interactions in buffer and serum. Journal of Fluorescence. 2016;**26**(4):1479-1487. DOI: 10.1007/

[13] Baaske P, Wienken CJ, Reineck P,

thermophoresis for quantifying the buffer dependence of aptamer binding. Angewandte Chemie International Edition. 2010;**49**(12):2238-2241. DOI:

[14] Radom F, Jurek PM, Mazurek MP, Otlewski J, Jeleń F. Aptamers: Molecules of great potential. Biotechnology Advances. 2013;**31**(8):1260-1274. DOI: 10.1016/j.biotechadv.2013.04.007

[15] Parisien M, Major F. The MC-Fold and MC-Sym pipeline infers RNA structure from sequence data. Nature. 2008;**452**(7183):51-55. DOI: 10.1038/

[16] Lu XJ, Bussemaker HJ, Olson WK. DSSR: An integrated software tool for dissecting the spatial structure of RNA. Nucleic Acids Research.

2015;**43**(21):e142. DOI: 10.1093/nar/gkv716

[17] Chojnowski G, Waleń T, Bujnicki JM. RNA bricks—A database of RNA 3D

s10895-016-1840-1

Duhr S, Braun D. Optical

10.1002/anie.200903998

nature06684

bios.2004.11.006

c5an01824b

2005;**20**(12):2424-2434. DOI: 10.1016/j.

[3] Song KM, Lee S, Ban C. Aptamers and their biological applications. Sensors. 2012;**12**(1):612-631. DOI:

[4] Tuerk C, Gold L. Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase. Science. 1990;**249**(4968): 505-510. DOI: 10.1126/science.2200121

[5] Ellington AD, Szostak JW. In vitro selection of RNA molecules that bind specific ligands. Nature. 1990;**346**: 818-822. DOI: 10.1038/346818a0

[6] Robertson DL, Joyce GF. Selection in vitro of an RNA enzyme that specifically cleaves single-stranded DNA. Nature. 1990;**344**(6265):467-468.

[7] Hoinka J, Zotenko E, Friedman A, Sauna ZE, Przytycka TM. Identification of sequence-structure RNA binding motifs for SELEX-derived aptamers. Bioinformatics. 2012;**28**(12):i215-223. DOI: 10.1093/bioinformatics/bts210

[9] Tombelli S, Minunni M, Mascini M. Analytical applications of aptamers.

DOI: 10.1038/344467a0

[8] Hoinka J, Berezhnoy A, Sauna ZE, Gilboa E, Przytycka TM. AptaCluster—A method to cluster HT-SELEX aptamer pools and lessons from its application. Lecture Notes in Computer Science. 2014;**8394**(LNBI):115-128. DOI: 10.1007/978-3-319-05269-4\_9

10.1016/j.ydbio.2004.11.028

[2] Lipfert J, Doniach S, Das R, Herschlag D. Understanding nucleic acid-ion interactions. Annual Review of Biochemistry. 2014;**83**:813-841. DOI: 10.1146/annurev-biochem-060409-092720

10.3390/s120100612

**References**

biosensor for detection of adenosine triphosphate using a nanoporous gold platform. Bioelectrochemistry. 2013;**94**:47-52. DOI: 10.1016/j. bioelechem.2013.05.005

[33] Zhu B, Alsager OA, Kumar S, Hodgkiss JM, Travas-Sejdic J. Labelfree electrochemical aptasensor for femtomolar detection of 17β-estradiol. Biosensors & Bioelectronics. 2015;**70**:398-403. DOI: 10.1016/j. bios.2015.03.050

[34] Yan M, Sun G, Liu F, Lu J, Jinghua Yu XS. Investigations on the interface of nucleic acid aptamers and binding targets. Analytica Chimica Acta. 2013;**798**:33-39. DOI: 10.1039/ C8AN01467A

[35] Guo Y, Wang Y, Liu S, Yu J, Wang H, Wang Y, et al. Label-free and highly sensitive electrochemical detection of *E. coli* based on rolling circle amplifications coupled peroxidase-mimicking DNAzyme amplification. Biosensors & Bioelectronics. 2016;**75**:315-319. DOI: 10.1016/j.bios.2015.08.031

[36] Peinetti AS, Ceretti H, Mizrahi M, González GA, Ramírez SA, Requejo FG, et al. Confined gold nanoparticles enhance the detection of small molecules in label-free impedance aptasensors. Nanoscale. 2015;**7**(17):7763-7769. DOI: 10.1039/ c5nr01429h

[37] Gosai A, Hau Yeah BS, Nilsen-Hamilton M, Shrotriya P. Label free thrombin detection in presence of high concentration of albumin using an aptamer-functionalized nanoporous membrane. Biosensors & Bioelectronics. 2019;**126**:88-95. DOI: 10.1016/j. bios.2018.10.010

[38] Feng X, Liu K, Ning Y, Chen L, Deng L. A label-free aptasensor for rapid detection of H1N1 virus based on graphene oxide and polymerase-aided signal amplification. Nanomedicine and Nanotechnology. 2015;**6**(3):288. DOI: 10.4172/2157-7439.1000288

[39] Sadeghi AS, Ansari N, Ramezani M, Abnous K, Mohsenzadeh M, Taghdisi SM, et al. Optical and electrochemical aptasensors for the detection of amphenicols. Biosensors & Bioelectronics. 2018;**118**:137-152. DOI: 10.1016/j.bios.2018.07.045

[40] Du X, Jiang D, Hao N, Qian J, Dai L, Zhou L, et al. Building a threedimensional nano-bio interface for aptasensing: An analytical methodology based on steric hindrance initiated signal amplification effect. Analytical Chemistry. 2016;**88**(19):9622-9629. DOI: 10.1021/acs.analchem.6b02368

[41] Luka G, Ahmadi A, Najjaran H, Alocilja E, Derosa M, Wolthers K, et al. Microfluidics integrated biosensors: A leading technology towards lab-on-Achip and sensing applications. Sensors (Basel). 2015;**15**(12):30011-30031. DOI: 10.3390/s151229783

[42] Kang K, Sachan A, Nilsen-Hamilton M, Shrotriya P. Aptamer functionalized microcantilever sensors for cocaine detection. Langmuir. 2011;**27**(23):14696-14702. DOI: 10.1021/ la202067y

[43] Kang K, Nilsen-Hamilton M, Shrotriya P. Differential surface stress sensor for detection of chemical and biological species. Applied Physics Letters. 2008;**93**(14):14-17. DOI: 10.1063/1.2996411

[44] Zhai L, Wang T, Kang K, Zhao Y, Shrotriya P, Nilsen-Hamilton M. An RNA aptamer-based microcantilever sensor to detect the inflammatory marker, mouse lipocalin-2. Analytical Chemistry. 2012;**84**(20):8763-8770. DOI: 10.1021/ac3020643

[45] Lim YC, Kouzani AZ, Duan W, Dai XJ, Kaynak, A, Mair D. Design and evaluation of a microcantilever aptasensor. In: ISCAS

**139**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

Actuators, B:Chemical. 2016;**236**:474-479.

DOI: 10.1016/j.snb.2016.06.035

bios.2015.05.038

acs.analchem.5b04010

DOI: 10.3851/IMP1756

jinf.2016.01.014

10.1016/j.jinf.2014.05.015

[59] Rotherham LS, Maserumule C, Dheda K, Theron J, Khati M. Selection and application of ssDNA aptamers to

[53] Neves MADD, Blaszykowski C, Bokhari S, Thompson M. Ultra-high frequency piezoelectric aptasensor for the label-free detection of

cocaine. Biosensors & Bioelectronics. 2015;**72**:383-392. DOI: 10.1016/j.

[54] Neves MAD, Blaszykowski C, Thompson M. Utilizing a key aptamer structure-switching mechanism for the ultrahigh frequency detection of cocaine. Analytical Chemistry. 2016;**88**(6):3098-3106. DOI: 10.1021/

[55] Cai S, Yan J, Xiong H, Liu Y, Peng D, Liu Z. Investigations on the interface of nucleic acid aptamers and binding targets. The Analyst. 2018;**143**(22):5317-

5338. DOI: 10.1039/c8an01467a

[56] Faure-Perraud A, Métifiot M, Reigadas S, Recordon-Pinson P, Parissi V, Ventura M, et al. The guanine-quadruplex aptamer 93del inhibits HIV-1 replication ex vivo by interfering with viral entry, reverse transcription and integration. Antiviral Therapy. 2011;**16**(3):383-394.

[57] Tang XL, Wu SM, Xie Y, Song N, Guan Q, Yuan C, et al. Generation and application of ssDNA aptamers against glycolipid antigen ManLAM of Mycobacterium tuberculosis for TB diagnosis. The Journal of Infection. 2016;**72**(5):573-586. DOI: 10.1016/j.

[58] Tang XL, Zhou YX, Wu SM, Pan Q, Xia B, Zhang XL. CFP10 and ESAT6 aptamers as effective mycobacterial antigen diagnostic reagents. The Journal of Infection. 2014;**69**(6):569-580. DOI:

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

[46] Zhao Y, Schagerl M, Viechtbauer C, Loh KJ. Characterizing the conductivity and enhancing the Piezoresistivity of carbon nanotube-polymeric thin films. Materials (Basel). 2017;**10**(7):724. DOI:

2014: Proceedings of the 2014 IEEE International Symposium on Circuits and Systems, IEEE, Piscataway, NJ. 2014. pp. 221-224. DOI: 10.1109/ISCAS.2014.6865105

10.3390/ma10070724

DOI: 10.1021/ac011294p

bioelechem.2004.04.011

10.1089/nat.2012.0386

10.1016/j.bios.2016.11.061

[47] Liss M, Petersen B, Wolf H, Prohaska E. An aptamer-based quartz crystal protein biosensor. Analytical Chemistry. 2002;**74**(17):4488-4495.

[48] Schlensog MD, Gronewold TMA, Tewes M, Famulok M, Quandt E. A love-wave biosensor using nucleic acids as ligands. Sensors & Actuators,B:Chemical. 2004;**101**(3):308- 315. DOI: 10.1016/j.snb.2004.03.015

[49] Tombelli S, Minunni M, Luzi E, Mascini M. Aptamer-based biosensors for the detection of HIV-1 Tat protein. Bioelectrochemistry. 2005;**67**(2 Spec Issue):135-141. DOI: 10.1016/j.

[50] Wilson R, Cossins A, Nicolau DV, Missailidis S. The selection of DNA aptamers for two different epitopes of thrombin was not due to different partitioning methods. Nucleic Acid Therapeutics. 2013;**23**(1):88-92. DOI:

[51] Ahmad Raston NH, Nguyen VT, Gu MB. A new lateral flow strip assay (LFSA) using a pair of aptamers for the detection of vaspin. Biosensors & Bioelectronics. 2017;**93**:21-25. DOI:

[52] Luo Z, Zhang J, Wang Y, Chen J, Li Y, Duan Y. An aptamer based method for small molecules detection through monitoring salt-induced AuNPs aggregation and surface plasmon resonance (SPR) detection. Sensors &

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

2014: Proceedings of the 2014 IEEE International Symposium on Circuits and Systems, IEEE, Piscataway, NJ. 2014. pp. 221-224. DOI: 10.1109/ISCAS.2014.6865105

*Recent Advances in Analytical Chemistry*

biosensor for detection of adenosine triphosphate using a nanoporous gold platform. Bioelectrochemistry. 2013;**94**:47-52. DOI: 10.1016/j. bioelechem.2013.05.005

Nanotechnology. 2015;**6**(3):288. DOI:

[39] Sadeghi AS, Ansari N, Ramezani M, Abnous K, Mohsenzadeh M, Taghdisi SM, et al. Optical and electrochemical

Bioelectronics. 2018;**118**:137-152. DOI:

[40] Du X, Jiang D, Hao N, Qian J, Dai L, Zhou L, et al. Building a threedimensional nano-bio interface for aptasensing: An analytical methodology based on steric hindrance initiated signal amplification effect. Analytical Chemistry. 2016;**88**(19):9622-9629. DOI: 10.1021/acs.analchem.6b02368

[41] Luka G, Ahmadi A, Najjaran H, Alocilja E, Derosa M, Wolthers K, et al. Microfluidics integrated biosensors: A leading technology towards lab-on-Achip and sensing applications. Sensors (Basel). 2015;**15**(12):30011-30031. DOI:

10.3390/s151229783

la202067y

10.1063/1.2996411

DOI: 10.1021/ac3020643

[42] Kang K, Sachan A, Nilsen-Hamilton M, Shrotriya P. Aptamer functionalized microcantilever sensors for cocaine detection. Langmuir. 2011;**27**(23):14696-14702. DOI: 10.1021/

[43] Kang K, Nilsen-Hamilton M, Shrotriya P. Differential surface stress sensor for detection of chemical and biological species. Applied Physics Letters. 2008;**93**(14):14-17. DOI:

[44] Zhai L, Wang T, Kang K, Zhao Y, Shrotriya P, Nilsen-Hamilton M. An RNA aptamer-based microcantilever sensor to detect the inflammatory marker, mouse lipocalin-2. Analytical Chemistry. 2012;**84**(20):8763-8770.

[45] Lim YC, Kouzani AZ, Duan W, Dai XJ, Kaynak, A, Mair D. Design and evaluation of a microcantilever aptasensor. In: ISCAS

10.4172/2157-7439.1000288

aptasensors for the detection of amphenicols. Biosensors &

10.1016/j.bios.2018.07.045

[33] Zhu B, Alsager OA, Kumar S, Hodgkiss JM, Travas-Sejdic J. Labelfree electrochemical aptasensor for femtomolar detection of 17β-estradiol.

Biosensors & Bioelectronics. 2015;**70**:398-403. DOI: 10.1016/j.

[34] Yan M, Sun G, Liu F, Lu J, Jinghua Yu XS. Investigations on the interface of nucleic acid aptamers and binding targets. Analytica Chimica Acta. 2013;**798**:33-39. DOI: 10.1039/

[35] Guo Y, Wang Y, Liu S, Yu J, Wang H, Wang Y, et al. Label-free and highly sensitive electrochemical detection of *E. coli* based on rolling circle amplifications

DNAzyme amplification. Biosensors & Bioelectronics. 2016;**75**:315-319. DOI:

[36] Peinetti AS, Ceretti H, Mizrahi M,

[37] Gosai A, Hau Yeah BS, Nilsen-Hamilton M, Shrotriya P. Label free thrombin detection in presence of high concentration of albumin using an aptamer-functionalized nanoporous membrane. Biosensors & Bioelectronics.

2019;**126**:88-95. DOI: 10.1016/j.

[38] Feng X, Liu K, Ning Y, Chen L, Deng L. A label-free aptasensor for rapid detection of H1N1 virus based on graphene oxide and polymerase-aided signal amplification. Nanomedicine and

coupled peroxidase-mimicking

10.1016/j.bios.2015.08.031

González GA, Ramírez SA, Requejo FG, et al. Confined gold nanoparticles enhance the detection of small molecules in label-free impedance aptasensors. Nanoscale. 2015;**7**(17):7763-7769. DOI: 10.1039/

bios.2015.03.050

C8AN01467A

c5nr01429h

bios.2018.10.010

**138**

[46] Zhao Y, Schagerl M, Viechtbauer C, Loh KJ. Characterizing the conductivity and enhancing the Piezoresistivity of carbon nanotube-polymeric thin films. Materials (Basel). 2017;**10**(7):724. DOI: 10.3390/ma10070724

[47] Liss M, Petersen B, Wolf H, Prohaska E. An aptamer-based quartz crystal protein biosensor. Analytical Chemistry. 2002;**74**(17):4488-4495. DOI: 10.1021/ac011294p

[48] Schlensog MD, Gronewold TMA, Tewes M, Famulok M, Quandt E. A love-wave biosensor using nucleic acids as ligands. Sensors & Actuators,B:Chemical. 2004;**101**(3):308- 315. DOI: 10.1016/j.snb.2004.03.015

[49] Tombelli S, Minunni M, Luzi E, Mascini M. Aptamer-based biosensors for the detection of HIV-1 Tat protein. Bioelectrochemistry. 2005;**67**(2 Spec Issue):135-141. DOI: 10.1016/j. bioelechem.2004.04.011

[50] Wilson R, Cossins A, Nicolau DV, Missailidis S. The selection of DNA aptamers for two different epitopes of thrombin was not due to different partitioning methods. Nucleic Acid Therapeutics. 2013;**23**(1):88-92. DOI: 10.1089/nat.2012.0386

[51] Ahmad Raston NH, Nguyen VT, Gu MB. A new lateral flow strip assay (LFSA) using a pair of aptamers for the detection of vaspin. Biosensors & Bioelectronics. 2017;**93**:21-25. DOI: 10.1016/j.bios.2016.11.061

[52] Luo Z, Zhang J, Wang Y, Chen J, Li Y, Duan Y. An aptamer based method for small molecules detection through monitoring salt-induced AuNPs aggregation and surface plasmon resonance (SPR) detection. Sensors &

Actuators, B:Chemical. 2016;**236**:474-479. DOI: 10.1016/j.snb.2016.06.035

[53] Neves MADD, Blaszykowski C, Bokhari S, Thompson M. Ultra-high frequency piezoelectric aptasensor for the label-free detection of cocaine. Biosensors & Bioelectronics. 2015;**72**:383-392. DOI: 10.1016/j. bios.2015.05.038

[54] Neves MAD, Blaszykowski C, Thompson M. Utilizing a key aptamer structure-switching mechanism for the ultrahigh frequency detection of cocaine. Analytical Chemistry. 2016;**88**(6):3098-3106. DOI: 10.1021/ acs.analchem.5b04010

[55] Cai S, Yan J, Xiong H, Liu Y, Peng D, Liu Z. Investigations on the interface of nucleic acid aptamers and binding targets. The Analyst. 2018;**143**(22):5317- 5338. DOI: 10.1039/c8an01467a

[56] Faure-Perraud A, Métifiot M, Reigadas S, Recordon-Pinson P, Parissi V, Ventura M, et al. The guanine-quadruplex aptamer 93del inhibits HIV-1 replication ex vivo by interfering with viral entry, reverse transcription and integration. Antiviral Therapy. 2011;**16**(3):383-394. DOI: 10.3851/IMP1756

[57] Tang XL, Wu SM, Xie Y, Song N, Guan Q, Yuan C, et al. Generation and application of ssDNA aptamers against glycolipid antigen ManLAM of Mycobacterium tuberculosis for TB diagnosis. The Journal of Infection. 2016;**72**(5):573-586. DOI: 10.1016/j. jinf.2016.01.014

[58] Tang XL, Zhou YX, Wu SM, Pan Q, Xia B, Zhang XL. CFP10 and ESAT6 aptamers as effective mycobacterial antigen diagnostic reagents. The Journal of Infection. 2014;**69**(6):569-580. DOI: 10.1016/j.jinf.2014.05.015

[59] Rotherham LS, Maserumule C, Dheda K, Theron J, Khati M. Selection and application of ssDNA aptamers to

detect active TB from sputum samples. PLoS One. 2012;**7**(10):e46862. DOI: 10.1371/journal.pone.0046862

[60] Qin L, Zheng R, Ma Z, Feng Y, Liu Z, Yang H, et al. The selection and application of ssDNA aptamers against MPT64 protein in *Mycobacterium tuberculosis*. Clinical Chemistry and Laboratory Medicine. 2009;**47**(4):405- 411. DOI: 10.1515/CCLM.2009.097

[61] Zhu C, Liu J, Ling Y, Yang H, Liu Z, Zheng R, et al. Evaluation of the clinical value of ELISA based on MPT64 antibody aptamer for serological diagnosis of pulmonary tuberculosis. BMC Infectious Diseases. 2012;**12**:96. DOI: 10.1186/1471-2334-12-96

[62] Ngubane NAC, Gresh L, Pym A, Rubin EJ, Khati M. Selection of RNA aptamers against the M. tuberculosis EsxG protein using surface plasmon resonance-based SELEX. Biochemical and Biophysical Research Communications. 2014;**449**(1):114-119. DOI: 10.1016/j.bbrc.2014.04.163

[63] Aimaiti R, Qin L, Cao T, Yang H, Wang J, Lu J, et al. Identification and application of ssDNA aptamers against H37Rv in the detection of *Mycobacterium tuberculosis*. Applied Microbiology and Biotechnology. 2015;**99**(21):9073-9083. DOI: 10.1007/ s00253-015-6815-7

[64] Zhang XQ, Feng Y, Yao QQ, He F. Selection of a new *Mycobacterium tuberculosis* H37Rv aptamer and its application in the construction of a SWCNT/aptamer/Au-IDE MSPQC H37Rv sensor. Biosensors & Bioelectronics. 2017;**98**:261-266. DOI: 10.1016/j.bios.2017.05.043

[65] Joshi R, Janagama H, Dwivedi HP, Senthil Kumar TMA, Jaykus LA, Schefers J, et al. Selection, characterization, and application of DNA aptamers for the capture

and detection of *Salmonella enterica* serovars. Molecular and Cellular Probes. 2009;**23**(1):20-28. DOI: 10.1016/j. mcp.2008.10.006

[66] Ma X, Jiang Y, Jia F, Yu Y, Chen J, Wang Z. An aptamer-based electrochemical biosensor for the detection of Salmonella. Journal of Microbiological Methods. 2014;**98**(1):94-98. DOI: 10.1016/j. mimet.2014.01.003

[67] Han SR, Lee SW. In vitro selection of RNA aptamer specific to *Salmonella Typhimurium*. Journal of Microbiology and Biotechnology. 2013;**23**(6):878-884. DOI: 10.4014/jmb.1212.12033

[68] Moon J, Kim G, Lee S, Park S. Identification of *Salmonella typhimurium*-specific DNA aptamers developed using whole-cell SELEX and FACS analysis. Journal of Microbiological Methods. 2013;**95**(2):162-166. DOI: 10.1016/j.mimet.2013.08.005

[69] Duan N, Wu S, Chen X, Huang Y, Xia Y, Ma X, et al. Selection and characterization of aptamers against *Salmonella typhimurium* using wholebacterium systemic evolution of ligands by exponential enrichment (SELEX). Journal of Agricultural and Food Chemistry. 2013;**61**(13):3229-3234. DOI: 10.1021/jf400767d

[70] Lavu PSR, Mondal B, Ramlal S, Murali HS, Batra HV. Selection and characterization of aptamers using a modified whole cell bacterium SELEX for the detection of *Salmonella enterica Serovar Typhimurium*. ACS Combinatorial Science. 2016;**18**(6):292-301. DOI: 10.1021/ acscombsci.5b00123

[71] Yang M, Peng Z, Ning Y, Chen Y, Zhou Q, Deng L. Highly specific and cost-efficient detection of *Salmonella paratyphi* A combining aptamers with single-walled carbon nanotubes.

**141**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

[79] Cao X, Li S, Chen L, Ding H, Xu H, Huang Y, et al. Combining use of a panel of ssDNA aptamers in the detection of *Staphylococcus aureus*. Nucleic Acids Research. 2009;**37**(14):4621-4628. DOI:

[80] Borsa BA, Tuna BG, Hernandez FJ, Hernandez LI, Bayramoglu G, Arica MY, et al. *Staphylococcus aureus* detection in blood samples by silica nanoparticleoligonucleotides conjugates. Biosensors & Bioelectronics. 2016;**86**:27-32. DOI:

[81] Chang YC, Yang CY, Sun RL, Cheng YF, Kao WC, Yang PC. Rapid single cell detection of *Staphylococcus aureus* by aptamer-conjugated gold nanoparticles. Scientific Reports. 2013;**3**:1863. DOI:

10.1093/nar/gkp489

10.1016/j.bios.2016.06.023

10.1038/srep01863

[82] Ohk SH, Koo OK, Sen T,

Yamamoto CM, Bhunia AK. Antibodyaptamer functionalized fibre-optic biosensor for specific detection of Listeria monocytogenes from food. Journal of Applied Microbiology. 2010;**109**(3):808-817. DOI: 10.1111/j.1365-2672.2010.04709.x

[83] Bruno JG, Phillips T, Montez T, Garcia A, Sivils JC, Mayo MW, et al. Development of a fluorescent enzyme-linked DNA aptamermagnetic bead sandwich assay and portable fluorometer for sensitive and rapid listeria detection. Journal of Fluorescence. 2015;**25**(1):173-183. DOI:

10.1007/s10895-014-1495-8

jbiotec.2013.07.027

[84] Suh SH, Jaykus LA. Nucleic acid aptamers for capture and detection of Listeria spp. Journal of Biotechnology. 2013;**167**(4):454-461. DOI: 10.1016/j.

[85] Lee SH, Ahn JY, Lee KA, Um HJ, Sekhon SS, Sun Park T, et al. Analytical bioconjugates, aptamers, enable specific quantitative detection of Listeria monocytogenes. Biosensors &

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

Sensors (Switzerland). 2013;**13**(5):6865-

[72] Hyeon JY, Chon JW, Choi IS, Park C, Kim DE, Seo KH. Development of RNA aptamers for detection of *Salmonella enteritidis*. Journal of Microbiological Methods. 2012;**89**(1):79-82. DOI: 10.1016/j.mimet.2012.01.014

[73] Bayraç C, Eyidoğan F, Avni Öktem H. DNA aptamer-based colorimetric detection

Biosensors & Bioelectronics. 2017;**98**:22-28.

[74] DeGrasse JA. A single-stranded DNA aptamer that selectively binds to *Staphylococcus aureus* enterotoxin B. PLoS One. 2012;**7**(3):e33410. DOI: 10.1371/journal.pone.0033410

[75] Huang Y, Chen X, Duan N, Wu S, Wang Z, Wei X, et al. Selection and characterization of DNA aptamers against *Staphylococcus aureus* enterotoxin C1. Food Chemistry. 2015;**166**:623-629. DOI: 10.1016/j.foodchem.2014.06.039

[76] Hong KL, Battistella L, Salva AD, Williams RM, Sooter LJ. In vitro selection of single-stranded DNA molecular recognition elements against *S. Aureus* alpha toxin and sensitive detection in human serum. International Journal of Molecular Sciences. 2015;**16**(2):2794- 2809. DOI: 10.3390/ijms16022794

[77] Ferreira IM, de Souza Lacerda CM, de Faria LS, Corrêa CR, de Andrade ASR. Selection of peptidoglycanspecific aptamers for bacterial cells identification. Applied Biochemistry and Biotechnology. 2014;**174**(7):2548-2556. DOI: 10.1007/s12010-014-1206-6

[78] Stoltenburg R, Schubert T, Strehlitz B. In vitro selection and interaction studies of a DNA aptamer targeting Protein A. PLoS One. 2015;**10**(7):e0134403. DOI: 10.1371/journal.pone.0134403

platform for *Salmonella enteritidis*.

DOI: 10.1016/j.bios.2017.06.029

6881. DOI: 10.3390/s130506865

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

Sensors (Switzerland). 2013;**13**(5):6865- 6881. DOI: 10.3390/s130506865

*Recent Advances in Analytical Chemistry*

[60] Qin L, Zheng R, Ma Z, Feng Y, Liu Z, Yang H, et al. The selection and application of ssDNA aptamers against MPT64 protein in *Mycobacterium tuberculosis*. Clinical Chemistry and Laboratory Medicine. 2009;**47**(4):405- 411. DOI: 10.1515/CCLM.2009.097

[61] Zhu C, Liu J, Ling Y, Yang H, Liu Z, Zheng R, et al. Evaluation of the clinical value of ELISA based on MPT64

[62] Ngubane NAC, Gresh L, Pym A, Rubin EJ, Khati M. Selection of RNA aptamers against the M. tuberculosis EsxG protein using surface plasmon resonance-based SELEX. Biochemical

Communications. 2014;**449**(1):114-119.

[63] Aimaiti R, Qin L, Cao T, Yang H, Wang J, Lu J, et al. Identification and application of ssDNA aptamers against H37Rv in the detection of *Mycobacterium tuberculosis*. Applied Microbiology and Biotechnology. 2015;**99**(21):9073-9083. DOI: 10.1007/

[64] Zhang XQ, Feng Y, Yao QQ, He F. Selection of a new *Mycobacterium tuberculosis* H37Rv aptamer and its application in the construction of a SWCNT/aptamer/Au-IDE MSPQC H37Rv sensor. Biosensors & Bioelectronics. 2017;**98**:261-266. DOI:

[65] Joshi R, Janagama H, Dwivedi HP,

and Biophysical Research

s00253-015-6815-7

10.1016/j.bios.2017.05.043

Senthil Kumar TMA, Jaykus LA, Schefers J, et al. Selection, characterization, and application of DNA aptamers for the capture

DOI: 10.1016/j.bbrc.2014.04.163

antibody aptamer for serological diagnosis of pulmonary tuberculosis. BMC Infectious Diseases. 2012;**12**:96. DOI: 10.1186/1471-2334-12-96

detect active TB from sputum samples. PLoS One. 2012;**7**(10):e46862. DOI: 10.1371/journal.pone.0046862

and detection of *Salmonella enterica* serovars. Molecular and Cellular Probes. 2009;**23**(1):20-28. DOI: 10.1016/j.

[66] Ma X, Jiang Y, Jia F, Yu Y, Chen J,

[67] Han SR, Lee SW. In vitro selection of RNA aptamer specific to *Salmonella Typhimurium*. Journal of Microbiology and Biotechnology. 2013;**23**(6):878-884.

Wang Z. An aptamer-based electrochemical biosensor for the detection of Salmonella. Journal of Microbiological Methods. 2014;**98**(1):94-98. DOI: 10.1016/j.

DOI: 10.4014/jmb.1212.12033

[68] Moon J, Kim G, Lee S, Park S. Identification of *Salmonella* 

*typhimurium*-specific DNA aptamers developed using whole-cell SELEX and FACS analysis. Journal of Microbiological Methods. 2013;**95**(2):162-166. DOI: 10.1016/j.mimet.2013.08.005

[69] Duan N, Wu S, Chen X, Huang Y, Xia Y, Ma X, et al. Selection and characterization of aptamers against *Salmonella typhimurium* using wholebacterium systemic evolution of ligands by exponential enrichment (SELEX). Journal of Agricultural and Food

Chemistry. 2013;**61**(13):3229-3234. DOI:

[70] Lavu PSR, Mondal B, Ramlal S, Murali HS, Batra HV. Selection and characterization of aptamers using a modified whole cell bacterium SELEX for the detection of *Salmonella* 

[71] Yang M, Peng Z, Ning Y, Chen Y, Zhou Q, Deng L. Highly specific and cost-efficient detection of *Salmonella paratyphi* A combining aptamers with single-walled carbon nanotubes.

*enterica Serovar Typhimurium*. ACS Combinatorial Science. 2016;**18**(6):292-301. DOI: 10.1021/

acscombsci.5b00123

10.1021/jf400767d

mcp.2008.10.006

mimet.2014.01.003

**140**

[72] Hyeon JY, Chon JW, Choi IS, Park C, Kim DE, Seo KH. Development of RNA aptamers for detection of *Salmonella enteritidis*. Journal of Microbiological Methods. 2012;**89**(1):79-82. DOI: 10.1016/j.mimet.2012.01.014

[73] Bayraç C, Eyidoğan F, Avni Öktem H. DNA aptamer-based colorimetric detection platform for *Salmonella enteritidis*. Biosensors & Bioelectronics. 2017;**98**:22-28. DOI: 10.1016/j.bios.2017.06.029

[74] DeGrasse JA. A single-stranded DNA aptamer that selectively binds to *Staphylococcus aureus* enterotoxin B. PLoS One. 2012;**7**(3):e33410. DOI: 10.1371/journal.pone.0033410

[75] Huang Y, Chen X, Duan N, Wu S, Wang Z, Wei X, et al. Selection and characterization of DNA aptamers against *Staphylococcus aureus* enterotoxin C1. Food Chemistry. 2015;**166**:623-629. DOI: 10.1016/j.foodchem.2014.06.039

[76] Hong KL, Battistella L, Salva AD, Williams RM, Sooter LJ. In vitro selection of single-stranded DNA molecular recognition elements against *S. Aureus* alpha toxin and sensitive detection in human serum. International Journal of Molecular Sciences. 2015;**16**(2):2794- 2809. DOI: 10.3390/ijms16022794

[77] Ferreira IM, de Souza Lacerda CM, de Faria LS, Corrêa CR, de Andrade ASR. Selection of peptidoglycanspecific aptamers for bacterial cells identification. Applied Biochemistry and Biotechnology. 2014;**174**(7):2548-2556. DOI: 10.1007/s12010-014-1206-6

[78] Stoltenburg R, Schubert T, Strehlitz B. In vitro selection and interaction studies of a DNA aptamer targeting Protein A. PLoS One. 2015;**10**(7):e0134403. DOI: 10.1371/journal.pone.0134403

[79] Cao X, Li S, Chen L, Ding H, Xu H, Huang Y, et al. Combining use of a panel of ssDNA aptamers in the detection of *Staphylococcus aureus*. Nucleic Acids Research. 2009;**37**(14):4621-4628. DOI: 10.1093/nar/gkp489

[80] Borsa BA, Tuna BG, Hernandez FJ, Hernandez LI, Bayramoglu G, Arica MY, et al. *Staphylococcus aureus* detection in blood samples by silica nanoparticleoligonucleotides conjugates. Biosensors & Bioelectronics. 2016;**86**:27-32. DOI: 10.1016/j.bios.2016.06.023

[81] Chang YC, Yang CY, Sun RL, Cheng YF, Kao WC, Yang PC. Rapid single cell detection of *Staphylococcus aureus* by aptamer-conjugated gold nanoparticles. Scientific Reports. 2013;**3**:1863. DOI: 10.1038/srep01863

[82] Ohk SH, Koo OK, Sen T, Yamamoto CM, Bhunia AK. Antibodyaptamer functionalized fibre-optic biosensor for specific detection of Listeria monocytogenes from food. Journal of Applied Microbiology. 2010;**109**(3):808-817. DOI: 10.1111/j.1365-2672.2010.04709.x

[83] Bruno JG, Phillips T, Montez T, Garcia A, Sivils JC, Mayo MW, et al. Development of a fluorescent enzyme-linked DNA aptamermagnetic bead sandwich assay and portable fluorometer for sensitive and rapid listeria detection. Journal of Fluorescence. 2015;**25**(1):173-183. DOI: 10.1007/s10895-014-1495-8

[84] Suh SH, Jaykus LA. Nucleic acid aptamers for capture and detection of Listeria spp. Journal of Biotechnology. 2013;**167**(4):454-461. DOI: 10.1016/j. jbiotec.2013.07.027

[85] Lee SH, Ahn JY, Lee KA, Um HJ, Sekhon SS, Sun Park T, et al. Analytical bioconjugates, aptamers, enable specific quantitative detection of Listeria monocytogenes. Biosensors &

Bioelectronics. 2015;**68**:272-280. DOI: 10.1016/j.bios.2015.01.009

[86] Bruno JG, Phillips T, Carrillo MP, Crowell R. Plastic-adherent DNA aptamer-magnetic bead and quantum dot sandwich assay for campylobacter detection. Journal of Fluorescence. 2009;**19**(3):427-435. DOI: 10.1007/ s10895-008-0429-8

[87] Amraee M, Oloomi M, Yavari A, Bouzari S. DNA aptamer identification and characterization for *E. coli* O157 detection using cell based SELEX method. Analytical Biochemistry. 2017;**536**:36-44. DOI: 10.1016/j.ab.2017.08.005

[88] Peng Z, Ling M, Ning Y, Deng L. Rapid fluorescent detection of *Escherichia coli* K88 based on DNA aptamer library as direct and specific reporter combined with immunomagnetic separation. Journal of Fluorescence. 2014;**24**(4):1159-1168. DOI: 10.1007/s10895-014-1396-x

[89] Kim YS, Song MY, Jurng J, Kim BC. Isolation and characterization of DNA aptamers against *Escherichia coli* using a bacterial cell-systematic evolution of ligands by exponential enrichment approach. Analytical Biochemistry. 2013;**436**(1):22-28. DOI: 10.1016/j. ab.2013.01.014

[90] Dua P, Ren S, Lee SW, Kim J, Shin H, Jeong O, et al. Cell-SELEX based identification of an RNA aptamer for *Escherichia coli* and Its use in various detection formats. Molecules and Cells. 2016;**39**(11):807-813. DOI: 10.1111/j.1369-7625.2012.00810.x

[91] Renders M, Miller E, Lam CH, Perrin DM. Whole cell-SELEX of aptamers with a tyrosine-like side chain against live bacteria. Organic & Biomolecular Chemistry. 2017;**15**(9):1980-1989. DOI: 10.1039/C6OB02451C

[92] Chen F, Zhou J, Luo F, Mohammed AB, Zhang XL. Aptamer from

whole-bacterium SELEX as new therapeutic reagent against virulent *Mycobacterium tuberculosis*. Biochemical and Biophysical Research Communications. 2007;**357**(3):743-748. DOI: 10.1016/j.bbrc.2007.04.007

[93] Pan Q, Wang Q, Sun X, Xia X, Wu S, Luo F, et al. Aptamer against mannose-capped lipoarabinomannan inhibits virulent *Mycobacterium tuberculosis* infection in mice and rhesus monkeys. Molecular Therapy. 2014;**22**(5):940-951. DOI: 10.1038/ mt.2014.31

[94] Sun X, Pan Q, Yuan C, Wang Q, Tang X-L, Ding K, et al. A single ssDNA aptamer binding to ManLAM of BCG enhances immunoprotective effects against tuberculosis. Journal of the American Chemical Society. 2016;**138**(36):11680-11689. DOI: 10.1021/jacs.6b05357

[95] Baig IA, Moon JY, Lee SC, Ryoo SW, Yoon MY. Development of ssDNA aptamers as potent inhibitors of *Mycobacterium tuberculosis* acetohydroxyacid synthase. Biochim Biophys Acta—Proteins Proteomics. 2015;**1854**(10):1338-1350. DOI: 10.1016/j.bbapap.2015.05.003

[96] Pan Q, Zhang XL, Wu HY, He PW, Wang F, Zhang MS, et al. Aptamers that preferentially bind type IVB pili and inhibit human monocytic-cell invasion by *Salmonella enterica Serovar typhi*. Antimicrobial Agents and Chemotherapy. 2005;**49**(10):4052-4060. DOI: 10.1128/ AAC.49.10.4052-4060.2005

[97] Zelada-Guillen GA, Riu J, Düzgün A, Rius FX. Immediate detection of living bacteria at ultralow concentrations using a carbon nanotube based potentiometrie aptasensor. Angewandte Chemie International Edition. 2009;**48**(40):7334-7337. DOI: 10.1002/anie.200902090

**143**

bbrc.2007.04.057

*Aptamers for Diagnostics with Applications for Infectious Diseases*

2014;**88**(4):1990-1999. DOI: 10.1128/

Azadbakht A. Ultra-sensitive aptasensor based on a GQD nanocomposite for detection of hepatitis C virus core antigen. Analytical Biochemistry. 2017;**534**:64-69. DOI: 10.1016/j.

[106] Sung HJ, Kayhan B, Ben-Yedidia T, Arnon R. A DNA aptamer prevents influenza infection by blocking the receptor binding region of the viral hemagglutinin. The Journal of Biological Chemistry. 2004;**279**(46):48410-48419.

[107] Misono TS, Kumar PKR. Selection of RNA aptamers against human influenza virus hemagglutinin using surface plasmon resonance. Analytical Biochemistry. 2005;**342**(2):312-317. DOI: 10.1016/j.ab.2005.04.013

DOI: 10.1074/jbc.M409059200

[108] Gopinath SCB, Misono TS, Kawasaki K, Mizuno T, Imai M, Odagiri T, et al. An RNA aptamer that distinguishes between closely related human influenza viruses and inhibits haemagglutinin-mediated membrane fusion. The Journal of General Virology. 2006;**87**(3):479-487. DOI: 10.1099/

[109] Cheng C, Dong J, Yao L, Chen A, Jia R, Huan L, et al. Potent inhibition of human influenza H5N1 virus by oligonucleotides derived by SELEX. Biochemical and Biophysical

2008;**366**(3):670-674. DOI: 10.1016/j.

[110] Choi SK, Lee C, Lee KS, Choe SY, Mo IP, Seong RH, et al. DNA aptamers against the receptor binding region of hemagglutinin prevent avian influenza viral infection. Molecules and Cells. 2011;**32**(6):527-533. DOI: 10.1007/

Research Communications.

vir.0.81508-0

bbrc.2007.11.183

s10059-011-0156-x

[105] Ghanbari K, Roushani M,

JVI.03312-13

ab.2017.07.016

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

[98] Wang K, Wu D, Chen Z, Zhang X, Yang X, Yang CJ, et al. Inhibition of the superantigenic activities of staphylococcal enterotoxin A by an aptamer antagonist. Toxicon. 2016;**119**:21-27. DOI: 10.1016/j.

toxicon.2016.05.006

[99] Vivekananda J, Salgado C, Millenbaugh NJ. DNA aptamers as a novel approach to neutralize *Staphylococcus aureus* α-toxin.

DOI: 10.1016/j.bbrc.2014.01.076

[100] Yamamoto R, Katahira M,

Biochemical and Biophysical Research Communications. 2014;**444**(3):433-438.

Nishikawa S, Baba T, Taira K, Kumar PKR. A novel RNA motif that binds efficiently and specifically to the Tat protein of HIV and inhibits the trans-activation by Tat of transcription in vitro and in vivo. Genes to Cells. 2000;**5**(5):371-388. DOI: 10.1046/j.1365-2443.2000.00330.x

[101] Minunni M, Tombelli S, Gullotto A, Luzi E, Mascini M. Development of biosensors with aptamers as bio-recognition element: The case of HIV-1 Tat protein. Biosensors & Bioelectronics. 2004;**20**(6):1149-1156. DOI: 10.1016/j.bios.2004.03.037

[102] Chen F, Hu Y, Li D, Chen H, Zhang XL. CS-SELEX generates high-affinity ssDNA aptamers as molecular probes for hepatitis C virus envelope glycoprotein E2. PLoS One. 2009;**4**(12):e8142. DOI:

10.1371/journal.pone.0008142

[103] Lee S, Kim YS, Jo M, Jin M, ki Lee D, Kim S. Chip-based detection of hepatitis C virus using RNA aptamers that specifically bind to HCV core antigen. Biochemical and Biophysical Research Communications. 2007;**358**(1):47-52. DOI: 10.1016/j.

[104] Shi S, Yu X, Gao Y, Xue B, Wu X, Wang X, et al. Inhibition of hepatitis C virus production by aptamers against the core protein. Journal of Virology.

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

[98] Wang K, Wu D, Chen Z, Zhang X, Yang X, Yang CJ, et al. Inhibition of the superantigenic activities of staphylococcal enterotoxin A by an aptamer antagonist. Toxicon. 2016;**119**:21-27. DOI: 10.1016/j. toxicon.2016.05.006

*Recent Advances in Analytical Chemistry*

10.1016/j.bios.2015.01.009

s10895-008-0429-8

Bioelectronics. 2015;**68**:272-280. DOI:

whole-bacterium SELEX as new therapeutic reagent against virulent *Mycobacterium tuberculosis*. Biochemical and Biophysical Research Communications. 2007;**357**(3):743-748.

DOI: 10.1016/j.bbrc.2007.04.007

mt.2014.31

10.1021/jacs.6b05357

[93] Pan Q, Wang Q, Sun X, Xia X, Wu S, Luo F, et al. Aptamer against mannose-capped lipoarabinomannan inhibits virulent *Mycobacterium tuberculosis* infection in mice and rhesus monkeys. Molecular Therapy. 2014;**22**(5):940-951. DOI: 10.1038/

[94] Sun X, Pan Q, Yuan C, Wang Q, Tang X-L, Ding K, et al. A single ssDNA aptamer binding to ManLAM of BCG enhances immunoprotective effects against tuberculosis. Journal of the American Chemical Society. 2016;**138**(36):11680-11689. DOI:

[95] Baig IA, Moon JY, Lee SC, Ryoo SW, Yoon MY. Development of ssDNA aptamers as potent inhibitors of *Mycobacterium tuberculosis*

acetohydroxyacid synthase. Biochim Biophys Acta—Proteins Proteomics. 2015;**1854**(10):1338-1350. DOI: 10.1016/j.bbapap.2015.05.003

[96] Pan Q, Zhang XL, Wu HY, He PW, Wang F, Zhang MS, et al. Aptamers that preferentially bind type IVB pili and inhibit human monocytic-cell invasion by *Salmonella enterica Serovar typhi*. Antimicrobial

Agents and Chemotherapy.

AAC.49.10.4052-4060.2005

10.1002/anie.200902090

[97] Zelada-Guillen GA, Riu J, Düzgün A, Rius FX. Immediate detection of living bacteria at ultralow concentrations using a carbon nanotube based potentiometrie aptasensor. Angewandte Chemie International Edition. 2009;**48**(40):7334-7337. DOI:

2005;**49**(10):4052-4060. DOI: 10.1128/

[86] Bruno JG, Phillips T, Carrillo MP, Crowell R. Plastic-adherent DNA aptamer-magnetic bead and quantum dot sandwich assay for campylobacter detection. Journal of Fluorescence. 2009;**19**(3):427-435. DOI: 10.1007/

[87] Amraee M, Oloomi M, Yavari A, Bouzari S. DNA aptamer identification and characterization for *E. coli* O157 detection using cell based SELEX method. Analytical Biochemistry. 2017;**536**:36-44.

[88] Peng Z, Ling M, Ning Y, Deng L. Rapid fluorescent detection of *Escherichia coli* K88 based on DNA aptamer library as direct and specific reporter combined with immunomagnetic separation. Journal of Fluorescence. 2014;**24**(4):1159-1168. DOI: 10.1007/s10895-014-1396-x

[89] Kim YS, Song MY, Jurng J, Kim BC. Isolation and characterization of DNA aptamers against *Escherichia coli* using a bacterial cell-systematic evolution of ligands by exponential enrichment approach. Analytical Biochemistry. 2013;**436**(1):22-28. DOI: 10.1016/j.

[90] Dua P, Ren S, Lee SW, Kim J, Shin H, Jeong O, et al. Cell-SELEX based identification of an RNA aptamer for *Escherichia coli* and Its use in various detection formats. Molecules and Cells. 2016;**39**(11):807-813. DOI: 10.1111/j.1369-7625.2012.00810.x

[91] Renders M, Miller E, Lam CH, Perrin DM. Whole cell-SELEX of aptamers with a tyrosine-like side chain against live bacteria. Organic & Biomolecular Chemistry. 2017;**15**(9):1980-1989. DOI:

[92] Chen F, Zhou J, Luo F, Mohammed AB, Zhang XL. Aptamer from

ab.2013.01.014

10.1039/C6OB02451C

DOI: 10.1016/j.ab.2017.08.005

**142**

[99] Vivekananda J, Salgado C, Millenbaugh NJ. DNA aptamers as a novel approach to neutralize *Staphylococcus aureus* α-toxin. Biochemical and Biophysical Research Communications. 2014;**444**(3):433-438. DOI: 10.1016/j.bbrc.2014.01.076

[100] Yamamoto R, Katahira M, Nishikawa S, Baba T, Taira K, Kumar PKR. A novel RNA motif that binds efficiently and specifically to the Tat protein of HIV and inhibits the trans-activation by Tat of transcription in vitro and in vivo. Genes to Cells. 2000;**5**(5):371-388. DOI: 10.1046/j.1365-2443.2000.00330.x

[101] Minunni M, Tombelli S, Gullotto A, Luzi E, Mascini M. Development of biosensors with aptamers as bio-recognition element: The case of HIV-1 Tat protein. Biosensors & Bioelectronics. 2004;**20**(6):1149-1156. DOI: 10.1016/j.bios.2004.03.037

[102] Chen F, Hu Y, Li D, Chen H, Zhang XL. CS-SELEX generates high-affinity ssDNA aptamers as molecular probes for hepatitis C virus envelope glycoprotein E2. PLoS One. 2009;**4**(12):e8142. DOI: 10.1371/journal.pone.0008142

[103] Lee S, Kim YS, Jo M, Jin M, ki Lee D, Kim S. Chip-based detection of hepatitis C virus using RNA aptamers that specifically bind to HCV core antigen. Biochemical and Biophysical Research Communications. 2007;**358**(1):47-52. DOI: 10.1016/j. bbrc.2007.04.057

[104] Shi S, Yu X, Gao Y, Xue B, Wu X, Wang X, et al. Inhibition of hepatitis C virus production by aptamers against the core protein. Journal of Virology.

2014;**88**(4):1990-1999. DOI: 10.1128/ JVI.03312-13

[105] Ghanbari K, Roushani M, Azadbakht A. Ultra-sensitive aptasensor based on a GQD nanocomposite for detection of hepatitis C virus core antigen. Analytical Biochemistry. 2017;**534**:64-69. DOI: 10.1016/j. ab.2017.07.016

[106] Sung HJ, Kayhan B, Ben-Yedidia T, Arnon R. A DNA aptamer prevents influenza infection by blocking the receptor binding region of the viral hemagglutinin. The Journal of Biological Chemistry. 2004;**279**(46):48410-48419. DOI: 10.1074/jbc.M409059200

[107] Misono TS, Kumar PKR. Selection of RNA aptamers against human influenza virus hemagglutinin using surface plasmon resonance. Analytical Biochemistry. 2005;**342**(2):312-317. DOI: 10.1016/j.ab.2005.04.013

[108] Gopinath SCB, Misono TS, Kawasaki K, Mizuno T, Imai M, Odagiri T, et al. An RNA aptamer that distinguishes between closely related human influenza viruses and inhibits haemagglutinin-mediated membrane fusion. The Journal of General Virology. 2006;**87**(3):479-487. DOI: 10.1099/ vir.0.81508-0

[109] Cheng C, Dong J, Yao L, Chen A, Jia R, Huan L, et al. Potent inhibition of human influenza H5N1 virus by oligonucleotides derived by SELEX. Biochemical and Biophysical Research Communications. 2008;**366**(3):670-674. DOI: 10.1016/j. bbrc.2007.11.183

[110] Choi SK, Lee C, Lee KS, Choe SY, Mo IP, Seong RH, et al. DNA aptamers against the receptor binding region of hemagglutinin prevent avian influenza viral infection. Molecules and Cells. 2011;**32**(6):527-533. DOI: 10.1007/ s10059-011-0156-x

[111] Park SY, Kim S, Yoon H, Kim K-B, Kalme SS, Oh S, et al. Selection of an antiviral RNA aptamer against hemagglutinin of the subtype H5 avian influenza virus. Nucleic Acid Therapy (Formerly Oligonucleotides). 2011;**21**(6):395-402. DOI: 10.1089/ nat.2011.0321

[112] Gopinath SCB, Kumar PKR. Aptamers that bind to the hemagglutinin of the recent pandemic influenza virus H1N1 and efficiently inhibit agglutination. Acta Biomaterialia. 2013;**9**(11):8932-8941. DOI: 10.1016/j.actbio.2013.06.016

[113] Wongphatcharachai M, Wang P, Enomoto S, Webby RJ, Gramer MR, Amonsin A, et al. Neutralizing DNA aptamers against swine influenza H3N2 viruses. Journal of Clinical Microbiology. 2013;**51**(1):46-54. DOI: 10.1128/JCM.02118-12

[114] Suenaga E, Kumar PKR. An aptamer that binds efficiently to the hemagglutinins of highly pathogenic avian influenza viruses (H5N1 and H7N7) and inhibits hemagglutininglycan interactions. Acta Biomaterialia. 2014;**10**(3):1314-1323. DOI: 10.1016/j. actbio.2013.12.034

[115] Woo HM, Lee JM, Yim S, Jeong YJ. Isolation of single-stranded DNA aptamers that distinguish influenza virus hemagglutinin subtype H1 from H5. PLoS One. 2015;**10**(4):e0125060. DOI: 10.1371/journal.pone.0125060

[116] Zhang Y, Yu Z, Jiang F, Fu P, Shen J, Wu W, et al. Two DNA aptamers against avian influenza H9N2 virus prevent viral infection in cells. PLoS One. 2015;**10**(3):e0123060. DOI: 10.1371/journal.pone.0123060

[117] Lai HC, Wang CH, Liou TM, Bin LG. Influenza A virus-specific aptamers screened by using an integrated microfluidic system. Lab on a Chip. 2014;**14**(12):2002-2013. DOI: 10.1016/j.vetpar.2015.05.004

[118] Nguyen VT, Bin SH, Kim BC, Kim SK, Song CS, Gu MB. Highly sensitive sandwich-type SPR based detection of whole H5Nx viruses using a pair of aptamers. Biosensors & Bioelectronics. 2016;**86**:293-300. DOI: 10.1016/j. bios.2016.06.064

[119] Liu J, Yang Y, Hu B, Ma ZY, Huang HP, Yu Y, et al. Development of HBsAgbinding aptamers that bind HepG2.2.15 cells via HBV surface antigen. Virologica Sinica. 2010;**25**(1):27-35. DOI: 10.1007/ s12250-010-3091-7

[120] Toscano-Garibay JD, Benítez-Hess ML, Alvarez-Salas LM. Isolation and characterization of an RNA aptamer for the HPV-16 E7 oncoprotein. Archives of Medical Research. 2011;**42**(2):88-96. DOI: 10.1016/j.arcmed.2011.02.005

[121] Rahim Ruslinda A, Tanabe K, Ibori S, Wang X, Kawarada H. Effects of diamond-FET-based RNA aptamer sensing for detection of real sample of HIV-1 Tat protein. Biosensors & Bioelectronics. 2013;**40**(1):277-282. DOI: 10.1016/j.bios.2012.07.048

[122] Zhou J, Swiderski P, Li H, Zhang J, Neff CP, Akkina R, et al. Selection, characterization and application of new RNA HIV gp 120 aptamers for facile delivery of Dicer substrate siRNAs into HIV infected cells. Nucleic Acids Research. 2009;**37**(9):3094-3109. DOI: 10.1093/nar/gkp185

[123] Prokofjeva M, Tsvetkov V, Basmanov D, Varizhuk A, Lagarkova M, Smirnov I, et al. Anti-HIV activities of intramolecular G4 and Non-G4 oligonucleotides. Nucleic Acid Therapeutics. 2017;**27**(1):56-66. DOI: 10.1089/nat.2016.0624

[124] Tuerk C, MacDougal S, Gold L. RNA pseudoknots that inhibit human immunodeficiency virus type 1 reverse transcriptase. Proceedings of the National Academy of Sciences of the United States of America. 1992;**89**(15):6988-6992. DOI: 10.1073/pnas.89.15.6988

**145**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

1999;**274**(18):12730-12737. DOI:

[132] Jing N, Hogan ME. Structure-

[133] Esposito V, Pirone L, Mayol L, Pedone E, Virgilio A, Galeone A. Exploring the binding of d(GGGT)4 to the HIV-1 integrase: An approach to investigate G-quadruplex aptamer/ target protein interactions. Biochimie.

2016;**127**:19-22. DOI: 10.1016/j.

[134] De Soultrait VR, Lozach PY, Altmeyer R, Tarrago-Litvak L, Litvak S, Andréola ML. DNA aptamers derived from HIV-1 RNase H inhibitors are strong anti-integrase agents. Journal of Molecular Biology. 2002;**324**(2):195-203. DOI: 10.1016/S0022-2836(02)01064-1

[135] Phan AT, Kuryavyi V, Ma J-B, Faure A, Andreola M-L, Patel DJ. From the cover: An interlocked dimeric parallel-stranded DNA quadruplex: A potent inhibitor of HIV-1 integrase. Proceedings of the National Academy of Sciences of the United States of America. 2005;**102**(3):634-639. DOI:

10.1073/pnas.0406278102

Lee JH, You JC. Selection and stabilization of the RNA aptamers against the human immunodeficiency virus type-1 nucleocapsid protein. Biochemical and Biophysical Research Communications. 2002;**291**(4):925-931.

DOI: 10.1006/bbrc.2002.6521

Ellington A, Rein A, Prasad VR. RNA aptamers directed to human immunodeficiency virus type 1 gag polyprotein bind to the matrix and nucleocapsid domains and inhibit

[136] Kim SJ, Kim MY, Jeong S, Kim SJ,

[137] Ramalingam D, Duclair S, Datta SAK,

biochi.2016.04.013

10.1074/jbc.274.18.12730

activity of tetrad-forming oligonucleotides as a potent anti- HIV therapeutic drug. The Journal of Biological Chemistry. 1998;**273**(52):34992-34999. DOI:

10.1074/jbc.273.52.34992

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

[125] Schneider DJ, Feigon J, Hostomsky Z, Gold L. High-affinity ssDNA inhibitors of the reverse transcriptase of type 1 human immunodeficiency virus. Biochemistry. 1995;**34**(29):9599-9610.

[126] Mosing RK, Mendonsa SD, Bowser MT. Capillary electrophoresis-SELEX selection of aptamers with affinity for HIV-1 reverse transcriptase. Analytical Chemistry. 2005;**77**(19):6107-6112. DOI:

[127] Somasunderam A, Ferguson MR, Rojo DR, Thiviyanathan V, Li X, O'Brien WA, et al. Combinatorial

selection, inhibition, and antiviral activity of DNA thioaptamers targeting the RNase H domain of HIV-1 reverse transcriptase. Biochemistry. 2005;**44**(30):10388-10395.

[128] DeStefano JJ, Nair GR. Novel aptamer inhibitors of human immunodeficiency

Oligonucleotides. 2008;**18**(2):133-144.

[129] Ferreira-Bravo IA, Cozens C, Holliger P, DeStefano JJ. Selection of 2′-deoxy-2′-fluoroarabinonucleotide (FANA) aptamers that bind HIV-1 reverse transcriptase with picomolar affinity. Nucleic Acids Research. 2015;**43**(20):9587-9599. DOI: 10.1093/

[130] Sánchez-Luque FJ, Stich M,

Efficient HIV-1 inhibition by a 16 nt-long RNA aptamer designed by combining in vitro selection and in silico optimisation strategies. Scientific Reports. 2014;**1**(4):6242. DOI: 10.1038/

Manrubia S, Briones C, Berzal-Herranz A.

[131] Boiziau C, Dausse E, Yurchenko L, Toulmé JJ. DNA aptamers selected against the HIV-1 trans-activationresponsive RNA element form RNA-DNA kissing complexes. The Journal of Biological Chemistry.

DOI: 10.1021/bi00029a037

10.1021/ac050836q

DOI: 10.1021/bi0507074

virus reverse transcriptase.

DOI: 10.1089/oli.2008.0103

nar/gkv1057

srep06242

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

[125] Schneider DJ, Feigon J, Hostomsky Z, Gold L. High-affinity ssDNA inhibitors of the reverse transcriptase of type 1 human immunodeficiency virus. Biochemistry. 1995;**34**(29):9599-9610. DOI: 10.1021/bi00029a037

*Recent Advances in Analytical Chemistry*

[112] Gopinath SCB, Kumar PKR. Aptamers that bind to the hemagglutinin of the recent

pandemic influenza virus H1N1 and efficiently inhibit agglutination. Acta Biomaterialia. 2013;**9**(11):8932-8941. DOI: 10.1016/j.actbio.2013.06.016

[113] Wongphatcharachai M, Wang P, Enomoto S, Webby RJ, Gramer MR, Amonsin A, et al. Neutralizing DNA aptamers against swine influenza H3N2 viruses. Journal of Clinical Microbiology. 2013;**51**(1):46-54. DOI: 10.1128/JCM.02118-12

[114] Suenaga E, Kumar PKR. An aptamer that binds efficiently to the hemagglutinins of highly pathogenic avian influenza viruses (H5N1 and H7N7) and inhibits hemagglutininglycan interactions. Acta Biomaterialia. 2014;**10**(3):1314-1323. DOI: 10.1016/j.

[115] Woo HM, Lee JM, Yim S, Jeong YJ. Isolation of single-stranded DNA aptamers that distinguish influenza virus hemagglutinin subtype H1 from H5. PLoS One. 2015;**10**(4):e0125060. DOI: 10.1371/journal.pone.0125060

[116] Zhang Y, Yu Z, Jiang F, Fu P, Shen J, Wu W, et al. Two DNA aptamers against avian influenza H9N2 virus prevent viral infection in cells. PLoS One. 2015;**10**(3):e0123060. DOI: 10.1371/journal.pone.0123060

[117] Lai HC, Wang CH, Liou TM, Bin LG. Influenza A virus-specific aptamers screened by using an

10.1016/j.vetpar.2015.05.004

integrated microfluidic system. Lab on a Chip. 2014;**14**(12):2002-2013. DOI:

actbio.2013.12.034

nat.2011.0321

[111] Park SY, Kim S, Yoon H, Kim K-B, Kalme SS, Oh S, et al. Selection of an antiviral RNA aptamer against hemagglutinin of the subtype H5 avian influenza virus. Nucleic Acid Therapy (Formerly Oligonucleotides). 2011;**21**(6):395-402. DOI: 10.1089/

[118] Nguyen VT, Bin SH, Kim BC, Kim SK, Song CS, Gu MB. Highly sensitive sandwich-type SPR based detection of whole H5Nx viruses using a pair of aptamers. Biosensors & Bioelectronics. 2016;**86**:293-300. DOI: 10.1016/j.

[119] Liu J, Yang Y, Hu B, Ma ZY, Huang HP, Yu Y, et al. Development of HBsAgbinding aptamers that bind HepG2.2.15 cells via HBV surface antigen. Virologica Sinica. 2010;**25**(1):27-35. DOI: 10.1007/

[120] Toscano-Garibay JD, Benítez-Hess ML,

characterization of an RNA aptamer for the HPV-16 E7 oncoprotein. Archives of Medical Research. 2011;**42**(2):88-96. DOI: 10.1016/j.arcmed.2011.02.005

Alvarez-Salas LM. Isolation and

[121] Rahim Ruslinda A, Tanabe K, Ibori S, Wang X, Kawarada H. Effects of diamond-FET-based RNA aptamer sensing for detection of real sample of HIV-1 Tat protein. Biosensors & Bioelectronics. 2013;**40**(1):277-282. DOI: 10.1016/j.bios.2012.07.048

[122] Zhou J, Swiderski P, Li H, Zhang J, Neff CP, Akkina R, et al. Selection, characterization and application of new RNA HIV gp 120 aptamers for facile delivery of Dicer substrate siRNAs into HIV infected cells. Nucleic Acids Research. 2009;**37**(9):3094-3109. DOI:

bios.2016.06.064

s12250-010-3091-7

10.1093/nar/gkp185

10.1089/nat.2016.0624

10.1073/pnas.89.15.6988

[123] Prokofjeva M, Tsvetkov V,

Basmanov D, Varizhuk A, Lagarkova M, Smirnov I, et al. Anti-HIV activities of intramolecular G4 and Non-G4 oligonucleotides. Nucleic Acid Therapeutics. 2017;**27**(1):56-66. DOI:

[124] Tuerk C, MacDougal S, Gold L. RNA pseudoknots that inhibit human immunodeficiency virus type 1 reverse transcriptase. Proceedings of the National Academy of Sciences of the United States of America. 1992;**89**(15):6988-6992. DOI:

**144**

[126] Mosing RK, Mendonsa SD, Bowser MT. Capillary electrophoresis-SELEX selection of aptamers with affinity for HIV-1 reverse transcriptase. Analytical Chemistry. 2005;**77**(19):6107-6112. DOI: 10.1021/ac050836q

[127] Somasunderam A, Ferguson MR, Rojo DR, Thiviyanathan V, Li X, O'Brien WA, et al. Combinatorial selection, inhibition, and antiviral activity of DNA thioaptamers targeting the RNase H domain of HIV-1 reverse transcriptase. Biochemistry. 2005;**44**(30):10388-10395. DOI: 10.1021/bi0507074

[128] DeStefano JJ, Nair GR. Novel aptamer inhibitors of human immunodeficiency virus reverse transcriptase. Oligonucleotides. 2008;**18**(2):133-144. DOI: 10.1089/oli.2008.0103

[129] Ferreira-Bravo IA, Cozens C, Holliger P, DeStefano JJ. Selection of 2′-deoxy-2′-fluoroarabinonucleotide (FANA) aptamers that bind HIV-1 reverse transcriptase with picomolar affinity. Nucleic Acids Research. 2015;**43**(20):9587-9599. DOI: 10.1093/ nar/gkv1057

[130] Sánchez-Luque FJ, Stich M, Manrubia S, Briones C, Berzal-Herranz A. Efficient HIV-1 inhibition by a 16 nt-long RNA aptamer designed by combining in vitro selection and in silico optimisation strategies. Scientific Reports. 2014;**1**(4):6242. DOI: 10.1038/ srep06242

[131] Boiziau C, Dausse E, Yurchenko L, Toulmé JJ. DNA aptamers selected against the HIV-1 trans-activationresponsive RNA element form RNA-DNA kissing complexes. The Journal of Biological Chemistry.

1999;**274**(18):12730-12737. DOI: 10.1074/jbc.274.18.12730

[132] Jing N, Hogan ME. Structureactivity of tetrad-forming oligonucleotides as a potent anti- HIV therapeutic drug. The Journal of Biological Chemistry. 1998;**273**(52):34992-34999. DOI: 10.1074/jbc.273.52.34992

[133] Esposito V, Pirone L, Mayol L, Pedone E, Virgilio A, Galeone A. Exploring the binding of d(GGGT)4 to the HIV-1 integrase: An approach to investigate G-quadruplex aptamer/ target protein interactions. Biochimie. 2016;**127**:19-22. DOI: 10.1016/j. biochi.2016.04.013

[134] De Soultrait VR, Lozach PY, Altmeyer R, Tarrago-Litvak L, Litvak S, Andréola ML. DNA aptamers derived from HIV-1 RNase H inhibitors are strong anti-integrase agents. Journal of Molecular Biology. 2002;**324**(2):195-203. DOI: 10.1016/S0022-2836(02)01064-1

[135] Phan AT, Kuryavyi V, Ma J-B, Faure A, Andreola M-L, Patel DJ. From the cover: An interlocked dimeric parallel-stranded DNA quadruplex: A potent inhibitor of HIV-1 integrase. Proceedings of the National Academy of Sciences of the United States of America. 2005;**102**(3):634-639. DOI: 10.1073/pnas.0406278102

[136] Kim SJ, Kim MY, Jeong S, Kim SJ, Lee JH, You JC. Selection and stabilization of the RNA aptamers against the human immunodeficiency virus type-1 nucleocapsid protein. Biochemical and Biophysical Research Communications. 2002;**291**(4):925-931. DOI: 10.1006/bbrc.2002.6521

[137] Ramalingam D, Duclair S, Datta SAK, Ellington A, Rein A, Prasad VR. RNA aptamers directed to human immunodeficiency virus type 1 gag polyprotein bind to the matrix and nucleocapsid domains and inhibit

virus production. Journal of Virology. 2011;**85**(1):305-314. DOI: 10.1128/ JVI.02626-09

[138] Jensen KB, Green L, MacDougal-Waugh S, Tuerk C. Characterization of an in vitro-selected RNA ligand to the HIV-1 rev protein. Journal of Molecular Biology. 1994;**235**(1):237-247. DOI: 10.1016/S0022-2836(05)80030-0

[139] Pang KM, Castanotto D, Li H, Scherer L, Rossi JJ. Incorporation of aptamers in the terminal loop of shRNAs yields an effective and novel combinatorial targeting strategy. Nucleic Acids Research. 2017;**46**(1):e6. DOI: 10.1093/nar/gkx980

[140] Kumar PKR, Machida K, Urvil PT, Kakiuchi N, Vishnuvardhan D, Shimotohno K, et al. Isolation of RNA aptamers specific to the NS3 protein of hepatitis C virus from a pool of completely random RNA. Virology. 1997;**237**(2):270-282. DOI: 10.1006/ viro.1997.8773

[141] Fukuda K, Vishnuvardhan D, Sekiya S, Hwang J, Kakiuchi N, Taira K, et al. Isolation and characterization of RNA aptamers specific for the hepatitis C virus nonstructural protein 3 protease. European Journal of Biochemistry. 2000;**267**(12):3685-3694. DOI: 10.1046/j.1432-1327.2000.01400.x

[142] Nishikawa F, Funaji K, Fukuda K, Nishikawa S. In vitro selection of RNA aptamers against the HCVNS3 helicase domain. Oligonucleotides. 2004;**14**:114. DOI: 10.1089/1545457041526335

[143] Kikuchi K, Umehara T, Fukuda K, Kuno A, Hasegawa T, Nishikawa S. A hepatitis C virus (HCV) internal ribosome entry site (IRES) domain III-IVtargeted aptamer inhibits translation by binding to an apical loop of domain IIId. Nucleic Acids Research. 2005;**33**(2): 683-692. DOI: 10.1093/nar/gki215

[144] Romero-López C, Barroso-delJesus A, Puerta-Fernández E, Berzal-Herranz A.

Interfering with hepatitis C virus IRES activity using RNA molecules identified by a novel in vitro selection method. Biological Chemistry. 2005;**386**(2):183- 190. DOI: 10.1515/BC.2005.023

[145] Romero-López C, Díaz-González R, Berzal-Herranz A. Inhibition of hepatitis C virus internal ribosome entry site-mediated translation by an RNA targeting the conserved IIIf domain. Cellular and Molecular Life Sciences. 2007;**64**(22):2994-3006. DOI: 10.1007/s00018-007-7345-y

[146] Romero-López C, Lahlali T, Berzal-Herranz B, Berzal-Herranz A. Development of optimized inhibitor RNAs allowing multisite-targeting of the HCV genome. Molecules. 2017;**22**(5):E861. DOI: 10.3390/ molecules22050861

[147] Bellecave P, Andreola M-L, Ventura M, Tarrago-Litvak L, Litvak S, Astier-Gin T. Selection of DNA aptamers that bind the RNA-dependent RNA polymerase of hepatitis C virus and inhibit viral RNA synthesis *in vitro*. Oligonucleotides. 2003;**13**(6):455-463. DOI: 10.1089/154545703322860771

[148] Bellecave P, Cazenave C, Rumi J, Staedel C, Cosnefroy O, Andreola ML, et al. Inhibition of hepatitis C virus (HCV) RNA polymerase by DNA aptamers: Mechanism of inhibition of in vitro RNA synthesis and effect on HCV-infected cells. Antimicrobial Agents and Chemotherapy. 2008;**52**(6):2097-2110. DOI: 10.1128/ AAC.01227-07

[149] Jones LA, Clancy LE, Rawlinson WD, White PA. High-affinity aptamers to subtype 3a hepatitis C virus polymerase display genotypic specificity. Antimicrobial Agents and Chemotherapy. 2006;**50**(9):3019-3027. DOI: 10.1128/AAC.01603-05

[150] Lee CH, Lee YJ, Kim JH, Lim JH, Kim J-H, Han W, et al. Inhibition of

**147**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

[157] Nicol C, Cesur O, Forrest S, Belyaeva TA, Bunka DHJ, Blair GE, et al. An RNA aptamer provides a novel approach for the induction of apoptosis by targeting the HPV16 E7 oncoprotein. PLoS One. 2013;**8**:e64781. DOI: 10.1371/

[158] Belyaeva T, Nicol C, Cesur Ö, Travé G, Blair G, Stonehouse N. An RNA aptamer targets the PDZ-binding motif of the HPV16 E6 oncoprotein. Cancers (Basel). 2014;**6**(3):1553-1569. DOI: 10.3390/

[159] Shum KT, Tanner JA. Differential inhibitory activities and stabilisation of DNA aptamers against the SARS coronavirus helicase. Chembiochem. 2008;**9**(18):3037-3045. DOI: 10.1002/

[160] Chen HL, Hsiao WH, Lee HC, Wu SC, Cheng JW. Selection and characterization of DNA

aptamers targeting all four serotypes of dengue viruses. PLoS One. 2015;**10**(6):e0131240. DOI: 10.1371/

[161] Liang HR, Hu GQ, Li L, Gao YW, Yang ST, Xia XZ. Aptamers targeting rabies virus-infected cells inhibit street rabies virus in vivo. International Immunopharmacology. 2014;**21**(2):

[162] Shubham S, Hoinka J, Banerjee S, Swanson E, Dillard JA, Lennemann NJ, et al. A 2′FY-RNA motif defines an aptamer for Ebolavirus secreted protein. Science Reports. 2018;**8**(1):12373. DOI: 10.1038/

journal.pone.0064781

cancers6031553

cbic.200800491

journal.pone.0131240

432-438. DOI: 10.1016/j. intimp.2014.03.020

s41598-018-30590-8

acs.analchem.7b02862

[163] Lee KH, Zeng H. Aptamerbased ELISA assay for highly specific and sensitive detection of Zika NS1 protein. Analytical Chemistry. 2017;**89**(23):12743-12748. DOI: 10.1021/

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

hepatitis C Virus (HCV) replication by specific RNA aptamers against HCV NS5B RNA replicase. Journal of Virology. 2013;**87**(12):7064-7074. DOI:

[151] Kwon HM, Lee KH, Han BW, Han MR, Kim DH, Kim DE. An RNA aptamer that specifically binds to the glycosylated hemagglutinin of avian influenza virus and suppresses viral infection in cells. PLoS One. 2014;**9**(5):e97574. DOI: 10.1371/journal.pone.0097574

[152] Yuan S, Zhang N, Singh K, Shuai H, Chu H, Zhou J, et al. Cross-protection of influenza A virus infection by a DNA aptamer targeting the PA endonuclease domain. Antimicrobial Agents and Chemotherapy. 2015;**59**(7):4082-4093.

[153] Feng H, Beck J, Nassal M, hong Hu K. A SELEX-screened aptamer of human hepatitis B virus RNA encapsidation signal suppresses viral replication. PLoS One. 2011;**6**(11):e27862. DOI: 10.1371/

[154] Zhang Z, Zhang J, Pei X, Zhang Q, Lu B, Zhang X, et al. An aptamer targets HBV core protein and suppresses HBV replication in HepG2.2.15 cells. International Journal of Molecular Medicine. 2014;**34**(5):1423-1429. DOI:

[155] Orabi A, Bieringer M, Geerlof A, Bruss V. An aptamer against the matrix binding domain on the hepatitis B virus capsid impairs virion formation. Journal of Virology. 2015;**89**(18):9281-9287.

[156] Nicol C, Bunka DHJ, Blair GE, Stonehouse NJ. Effects of single nucleotide changes on the binding and activity of RNA aptamers to human papillomavirus 16 E7 oncoprotein. Biochemical and Biophysical Research Communications. 2011;**405**(3):417-421.

DOI: 10.1016/j.bbrc.2011.01.044

DOI: 10.1128/AAC.00306-15

journal.pone.0027862

10.3892/ijmm.2014.1908

DOI: 10.1128/JVI.00466-15

10.1128/JVI.00405-13

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

hepatitis C Virus (HCV) replication by specific RNA aptamers against HCV NS5B RNA replicase. Journal of Virology. 2013;**87**(12):7064-7074. DOI: 10.1128/JVI.00405-13

*Recent Advances in Analytical Chemistry*

JVI.02626-09

virus production. Journal of Virology. 2011;**85**(1):305-314. DOI: 10.1128/

Interfering with hepatitis C virus IRES activity using RNA molecules identified by a novel in vitro selection method. Biological Chemistry. 2005;**386**(2):183-

[145] Romero-López C, Díaz-González R, Berzal-Herranz A. Inhibition of hepatitis C virus internal ribosome entry site-mediated translation by an RNA targeting the conserved IIIf domain. Cellular and Molecular Life Sciences. 2007;**64**(22):2994-3006. DOI: 10.1007/s00018-007-7345-y

[146] Romero-López C, Lahlali T, Berzal-

[147] Bellecave P, Andreola M-L, Ventura M, Tarrago-Litvak L, Litvak S, Astier-Gin T. Selection of DNA aptamers that bind the RNA-dependent RNA polymerase of hepatitis C virus and inhibit viral RNA synthesis *in vitro*. Oligonucleotides. 2003;**13**(6):455-463. DOI: 10.1089/154545703322860771

[148] Bellecave P, Cazenave C, Rumi J, Staedel C, Cosnefroy O, Andreola ML, et al. Inhibition of hepatitis C virus (HCV) RNA polymerase by DNA aptamers: Mechanism of inhibition of in vitro RNA synthesis and effect on HCV-infected cells. Antimicrobial

2008;**52**(6):2097-2110. DOI: 10.1128/

[149] Jones LA, Clancy LE, Rawlinson WD, White PA. High-affinity aptamers to subtype 3a hepatitis C virus polymerase display genotypic

specificity. Antimicrobial Agents and Chemotherapy. 2006;**50**(9):3019-3027.

[150] Lee CH, Lee YJ, Kim JH, Lim JH, Kim J-H, Han W, et al. Inhibition of

DOI: 10.1128/AAC.01603-05

Agents and Chemotherapy.

AAC.01227-07

Herranz B, Berzal-Herranz A. Development of optimized inhibitor RNAs allowing multisite-targeting of the HCV genome. Molecules. 2017;**22**(5):E861. DOI: 10.3390/

molecules22050861

190. DOI: 10.1515/BC.2005.023

[138] Jensen KB, Green L, MacDougal-Waugh S, Tuerk C. Characterization of an in vitro-selected RNA ligand to the HIV-1 rev protein. Journal of Molecular Biology. 1994;**235**(1):237-247. DOI: 10.1016/S0022-2836(05)80030-0

[139] Pang KM, Castanotto D, Li H, Scherer L, Rossi JJ. Incorporation of aptamers in the terminal loop of shRNAs yields an effective and novel combinatorial targeting strategy. Nucleic Acids Research. 2017;**46**(1):e6.

[140] Kumar PKR, Machida K, Urvil PT,

DOI: 10.1093/nar/gkx980

viro.1997.8773

Kakiuchi N, Vishnuvardhan D, Shimotohno K, et al. Isolation of RNA aptamers specific to the NS3 protein of hepatitis C virus from a pool of completely random RNA. Virology. 1997;**237**(2):270-282. DOI: 10.1006/

[141] Fukuda K, Vishnuvardhan D, Sekiya S, Hwang J, Kakiuchi N, Taira K, et al. Isolation and characterization of RNA aptamers specific for the hepatitis C virus nonstructural protein 3 protease. European Journal of

Biochemistry. 2000;**267**(12):3685-3694. DOI: 10.1046/j.1432-1327.2000.01400.x

[142] Nishikawa F, Funaji K, Fukuda K, Nishikawa S. In vitro selection of RNA aptamers against the HCVNS3 helicase domain. Oligonucleotides. 2004;**14**:114.

[143] Kikuchi K, Umehara T, Fukuda K, Kuno A, Hasegawa T, Nishikawa S. A hepatitis C virus (HCV) internal ribosome entry site (IRES) domain III-IVtargeted aptamer inhibits translation by binding to an apical loop of domain IIId. Nucleic Acids Research. 2005;**33**(2): 683-692. DOI: 10.1093/nar/gki215

[144] Romero-López C, Barroso-delJesus A, Puerta-Fernández E, Berzal-Herranz A.

DOI: 10.1089/1545457041526335

**146**

[151] Kwon HM, Lee KH, Han BW, Han MR, Kim DH, Kim DE. An RNA aptamer that specifically binds to the glycosylated hemagglutinin of avian influenza virus and suppresses viral infection in cells. PLoS One. 2014;**9**(5):e97574. DOI: 10.1371/journal.pone.0097574

[152] Yuan S, Zhang N, Singh K, Shuai H, Chu H, Zhou J, et al. Cross-protection of influenza A virus infection by a DNA aptamer targeting the PA endonuclease domain. Antimicrobial Agents and Chemotherapy. 2015;**59**(7):4082-4093. DOI: 10.1128/AAC.00306-15

[153] Feng H, Beck J, Nassal M, hong Hu K. A SELEX-screened aptamer of human hepatitis B virus RNA encapsidation signal suppresses viral replication. PLoS One. 2011;**6**(11):e27862. DOI: 10.1371/ journal.pone.0027862

[154] Zhang Z, Zhang J, Pei X, Zhang Q, Lu B, Zhang X, et al. An aptamer targets HBV core protein and suppresses HBV replication in HepG2.2.15 cells. International Journal of Molecular Medicine. 2014;**34**(5):1423-1429. DOI: 10.3892/ijmm.2014.1908

[155] Orabi A, Bieringer M, Geerlof A, Bruss V. An aptamer against the matrix binding domain on the hepatitis B virus capsid impairs virion formation. Journal of Virology. 2015;**89**(18):9281-9287. DOI: 10.1128/JVI.00466-15

[156] Nicol C, Bunka DHJ, Blair GE, Stonehouse NJ. Effects of single nucleotide changes on the binding and activity of RNA aptamers to human papillomavirus 16 E7 oncoprotein. Biochemical and Biophysical Research Communications. 2011;**405**(3):417-421. DOI: 10.1016/j.bbrc.2011.01.044

[157] Nicol C, Cesur O, Forrest S, Belyaeva TA, Bunka DHJ, Blair GE, et al. An RNA aptamer provides a novel approach for the induction of apoptosis by targeting the HPV16 E7 oncoprotein. PLoS One. 2013;**8**:e64781. DOI: 10.1371/ journal.pone.0064781

[158] Belyaeva T, Nicol C, Cesur Ö, Travé G, Blair G, Stonehouse N. An RNA aptamer targets the PDZ-binding motif of the HPV16 E6 oncoprotein. Cancers (Basel). 2014;**6**(3):1553-1569. DOI: 10.3390/ cancers6031553

[159] Shum KT, Tanner JA. Differential inhibitory activities and stabilisation of DNA aptamers against the SARS coronavirus helicase. Chembiochem. 2008;**9**(18):3037-3045. DOI: 10.1002/ cbic.200800491

[160] Chen HL, Hsiao WH, Lee HC, Wu SC, Cheng JW. Selection and characterization of DNA aptamers targeting all four serotypes of dengue viruses. PLoS One. 2015;**10**(6):e0131240. DOI: 10.1371/ journal.pone.0131240

[161] Liang HR, Hu GQ, Li L, Gao YW, Yang ST, Xia XZ. Aptamers targeting rabies virus-infected cells inhibit street rabies virus in vivo. International Immunopharmacology. 2014;**21**(2): 432-438. DOI: 10.1016/j. intimp.2014.03.020

[162] Shubham S, Hoinka J, Banerjee S, Swanson E, Dillard JA, Lennemann NJ, et al. A 2′FY-RNA motif defines an aptamer for Ebolavirus secreted protein. Science Reports. 2018;**8**(1):12373. DOI: 10.1038/ s41598-018-30590-8

[163] Lee KH, Zeng H. Aptamerbased ELISA assay for highly specific and sensitive detection of Zika NS1 protein. Analytical Chemistry. 2017;**89**(23):12743-12748. DOI: 10.1021/ acs.analchem.7b02862

[164] Que-Gewirth NS, Sullenger BA. Gene therapy progress and prospects: RNA aptamers. Gene Therapy. 2007;**14**(4):283-291. DOI: 10.1038/ sj.gt.3302900

[165] Kaur H, Bruno JG, Kumar A, Sharma TK. Aptamers in the therapeutics and diagnostics pipelines. Theranostics. 2018;**8**(15):4016-4032. DOI: 10.7150/thno.25958

[166] O'Sullivan CK. Aptasensors—The future of biosensing? Analytical and Bioanalytical Chemistry. 2002;**372**:44-48. DOI: 10.1007/s00216-001-1189-3

[167] Shamah SM, Healy JM, Cload ST. Complex target SELEX. Accounts of Chemical Research. 2008;**41**:130-138. DOI: 10.1021/ar700142z

[168] Lim YC, Kouzani AZ, Duan W. Aptasensors: A review. Journal of Biomedical Nanotechnology. 2010;**6**(2): 93-105. DOI: 10.1166/jbn.2010.1103

[169] Dhiman A, Kalra P, Bansal V, Bruno JG, Sharma TK. Aptamer-based pointof-care diagnostic platforms. Sensors Actuators, B Chemical. 2017;**246**: 535-553. DOI: 10.1016/j.snb.2017.02.060

[170] Sharma TK. The point behind translation of aptamers for point of care diagnostics. Aptamers (Synthetic Antibodies). 2016;**3**:36-42

[171] Jayasena SD. Aptamers: An emerging class of molecules that rival antibodies in diagnostics. Clinical Chemistry. 1999;**45**:1628-1650

[172] Zhang P, Zhao N, Zeng Z, Chang CC, Zu Y. Combination of an aptamer probe to CD4 and antibodies for multicolored cell phenotyping. American Journal of Clinical Pathology. 2010;**134**(4):586-593. DOI: 10.1309/AJCP55KQYWSGZRKC

[173] Abdeevaa IA, Maloshenoka LG, Pogorelkoab GV, Mokrykovaa MV, Bruskin SA. RNA-aptamers—As targeted inhibitors of protein functions in plants. Journal of Plant Physiology. 2019;**232**: 127-129. DOI: 10.1016/j.jplph.2018.10.026

[174] Konopka K, Lee NS, Rossi J, Düzgüneş N. Rev-binding aptamer and CMV promoter act as decoys to inhibit HIV replication. Gene. 2000;**255**(2):235-244. DOI: 10.1016/ S0378-1119(00)00334-6

[175] Chaloin L. Endogenous expression of a high-affinity pseudoknot RNA aptamer suppresses replication of HIV-1. Nucleic Acids Research. 2002;**30**(18):4001-4008. DOI: 10.1093/ nar/gkf522

[176] Soh JH, Lin Y, Rana S, Ying JY, Stevens MM. Colorimetric detection of small molecules in complex matrixes via target-mediated growth of aptamer-functionalized gold nanoparticles. Analytical Chemistry. 2015;**87**(15):7644-7652. DOI: 10.1021/ acs.analchem.5b00875

[177] Ruscito A, DeRosa MC. Smallmolecule binding aptamers: Selection strategies, characterization, and applications. Frontiers in Chemistry. 2016;**4**(14):1-14. DOI: 10.3389/ fchem.2016.00014

[178] Liu A, Zhang Y, Chen W, Wang X, Chen F. Gold nanoparticle-based colorimetric detection of staphylococcal enterotoxin B using ssDNA aptamers. European Food Research and Technology. 2013;**237**(3):323-329. DOI: 10.1007/s00217-013-1995-9

[179] Shim WB, Kim MJ, Mun H, Kim MG. An aptamer-based dipstick assay for the rapid and simple detection of aflatoxin B1. Biosensors & Bioelectronics. 2014;**62**:288-294. DOI: 10.1016/j. bios.2014.06.059

[180] Candia J, Cheung F, Kotliarov Y, Fantoni G, Sellers B, Griesman T, et al. Assessment of variability in the SOMAscan assay. Scientific Reports.

**149**

*Aptamers for Diagnostics with Applications for Infectious Diseases*

engineering of multivalent aptamerfunctionalized nanointerface to enhance capture and release of circulating tumor cells. Angewandte Chemie International Edition. 2018;**131**:1-6. DOI: 1002/

[188] Hong P, Li W, Li J. Applications of aptasensors in clinical diagnostics. Sensors. 2012;**12**(2):1181-1193. DOI:

[189] Bhat VG, Chavan P, Ojha S, Nair PK.

diagnosis and management of dengue infections. The Open Microbiology

[190] Tsai WY, Youn HH, Brites C, Tsai JJ, Tyson J, Pedroso C, et al. Distinguishing secondary dengue virus infection from Zika virus infection with previous dengue by a combination of 3 simple serological tests. Clinical Infectious Diseases. 2017;**65**(11):1829-

1836. DOI: 10.1093/cid/cix672

10.1016/j.aca.2018.04.059

10.1021/ac302217u

10.7774/cevr.2017.6.2.160

tuberculosis

[194] WHO. Tuberculosis. 2018. Available from: https://www.who. int/news-room/fact-sheets/detail/

[191] Kim YJ, Kim HS, Chon JW, Kim DH, Hyeon JY, Seo KH. New colorimetric aptasensor for rapid on-site detection of *Campylobacter jejuni* and *Campylobacter coli* in chicken carcass samples. Analytica Chimica Acta. 2018;**1029**:78-85. DOI:

[192] Labib M, Zamay AS, Kolovskaya OS, Reshetneva IT, Zamay GS, Kibbee RJ, et al. Aptamer-based impedimetric sensor for bacterial typing. Analytical Chemistry. 2012;**84**(19):8114-8117. DOI:

[193] Yoon SY, Gee G, Hong KJ, Seo SH. Application of aptamers for assessment of vaccine efficacy. Clinical and Experimental Vaccine Research. 2017;**6**:160-163. DOI:

anie.201809337

10.3390/s120201181

Challenges in the laboratory

Journal. 2015;**9**:33-37. DOI: 10.2174/1874285801509010033

*DOI: http://dx.doi.org/10.5772/intechopen.84867*

[181] De Groote MA, Nahid P, Jarlsberg L, Johnson JL, Weiner M, Muzanyi G, et al. Elucidating novel serum biomarkers associated with pulmonary tuberculosis treatment. PLoS One. 2013;**8**(4):e61002. DOI: 10.1371/journal.pone.0061002

[182] Kraemer S, Vaught JD, Bock C, Gold L, Katilius E, Keeney TR, et al. From SOMAmer-based biomarker discovery to diagnostic and clinical applications: A SOMAmer-based, streamlined multiplex proteomic assay. PLoS One. 2011;**6**(10):e26332. DOI: 10.1371/journal.pone.0026332

[183] Lollo B, Steele F, Gold L. Beyond antibodies: New affinity reagents to unlock the proteome. Proteomics. 2014;**14**(6):638-644. DOI: 10.1002/

[184] Mehan MR, Ayers D, Thirstrup D, Xiong W, Ostroff RM, Brody EN, et al. Protein signature of lung cancer tissues. PLoS One. 2012;**7**(4):e35157. DOI: 10.1371/journal.pone.0035157

[185] Müller J, Friedrich M, Becher T, Braunstein J, Kupper T, Berdel P, et al. Monitoring of plasma levels of activated protein C using a clinically applicable oligonucleotide-based enzyme capture assay. Journal of Thrombosis and Haemostasis. 2012;**10**(3):390-398. DOI: 10.1111/j.1538-7836.2012.04623.x

[186] Yan X, Song Y, Liu J, Zhou N, Zhang CL, He L, et al. Two-dimensional porphyrin-based covalent organic framework: A novel platform for sensitive epidermal growth factor receptor and living cancer cell

detection. Biosensors & Bioelectronics. 2018;**5663**(18):30944-30948. DOI:

[187] Song Y, Shi Y, Huang M, Wang W, Wang Y, Cheng J, et al. Bioinspired

10.1016/j.bios.2018.11.047

pmic.201300187

2017;**7**(1):14248. DOI: 10.1038/

s41598-017-14755-5

*Aptamers for Diagnostics with Applications for Infectious Diseases DOI: http://dx.doi.org/10.5772/intechopen.84867*

2017;**7**(1):14248. DOI: 10.1038/ s41598-017-14755-5

*Recent Advances in Analytical Chemistry*

[164] Que-Gewirth NS, Sullenger BA. Gene therapy progress and prospects: RNA aptamers. Gene Therapy. 2007;**14**(4):283-291. DOI: 10.1038/

inhibitors of protein functions in plants. Journal of Plant Physiology. 2019;**232**: 127-129. DOI: 10.1016/j.jplph.2018.10.026

[175] Chaloin L. Endogenous expression of a high-affinity pseudoknot RNA aptamer suppresses replication of HIV-1. Nucleic Acids Research.

2002;**30**(18):4001-4008. DOI: 10.1093/

[176] Soh JH, Lin Y, Rana S, Ying JY, Stevens MM. Colorimetric detection of small molecules in complex matrixes via target-mediated growth of aptamer-functionalized gold nanoparticles. Analytical Chemistry. 2015;**87**(15):7644-7652. DOI: 10.1021/

[177] Ruscito A, DeRosa MC. Smallmolecule binding aptamers: Selection strategies, characterization, and applications. Frontiers in Chemistry. 2016;**4**(14):1-14. DOI: 10.3389/

[178] Liu A, Zhang Y, Chen W, Wang X, Chen F. Gold nanoparticle-based colorimetric detection of staphylococcal enterotoxin B using ssDNA aptamers.

Technology. 2013;**237**(3):323-329. DOI:

[179] Shim WB, Kim MJ, Mun H, Kim MG. An aptamer-based dipstick assay for the rapid and simple detection of aflatoxin B1. Biosensors & Bioelectronics. 2014;**62**:288-294. DOI: 10.1016/j.

[180] Candia J, Cheung F, Kotliarov Y, Fantoni G, Sellers B, Griesman T, et al. Assessment of variability in the SOMAscan assay. Scientific Reports.

European Food Research and

10.1007/s00217-013-1995-9

bios.2014.06.059

[174] Konopka K, Lee NS, Rossi J, Düzgüneş N. Rev-binding aptamer and CMV promoter act as decoys to inhibit HIV replication. Gene. 2000;**255**(2):235-244. DOI: 10.1016/

S0378-1119(00)00334-6

acs.analchem.5b00875

fchem.2016.00014

nar/gkf522

[165] Kaur H, Bruno JG, Kumar A, Sharma TK. Aptamers in the

DOI: 10.7150/thno.25958

DOI: 10.1021/ar700142z

therapeutics and diagnostics pipelines. Theranostics. 2018;**8**(15):4016-4032.

[166] O'Sullivan CK. Aptasensors—The future of biosensing? Analytical and Bioanalytical Chemistry. 2002;**372**:44-48.

[167] Shamah SM, Healy JM, Cload ST. Complex target SELEX. Accounts of Chemical Research. 2008;**41**:130-138.

DOI: 10.1007/s00216-001-1189-3

[168] Lim YC, Kouzani AZ, Duan W. Aptasensors: A review. Journal of Biomedical Nanotechnology. 2010;**6**(2): 93-105. DOI: 10.1166/jbn.2010.1103

[169] Dhiman A, Kalra P, Bansal V, Bruno JG, Sharma TK. Aptamer-based pointof-care diagnostic platforms. Sensors Actuators, B Chemical. 2017;**246**: 535-553. DOI: 10.1016/j.snb.2017.02.060

[170] Sharma TK. The point behind translation of aptamers for point of care diagnostics. Aptamers (Synthetic

Antibodies). 2016;**3**:36-42

[171] Jayasena SD. Aptamers: An emerging class of molecules that rival antibodies in diagnostics. Clinical Chemistry. 1999;**45**:1628-1650

[172] Zhang P, Zhao N, Zeng Z, Chang CC, Zu Y. Combination of an aptamer probe to CD4 and antibodies for multicolored cell phenotyping. American Journal of Clinical Pathology. 2010;**134**(4):586-593. DOI: 10.1309/AJCP55KQYWSGZRKC

[173] Abdeevaa IA, Maloshenoka LG, Pogorelkoab GV, Mokrykovaa MV, Bruskin SA. RNA-aptamers—As targeted

sj.gt.3302900

**148**

[181] De Groote MA, Nahid P, Jarlsberg L, Johnson JL, Weiner M, Muzanyi G, et al. Elucidating novel serum biomarkers associated with pulmonary tuberculosis treatment. PLoS One. 2013;**8**(4):e61002. DOI: 10.1371/journal.pone.0061002

[182] Kraemer S, Vaught JD, Bock C, Gold L, Katilius E, Keeney TR, et al. From SOMAmer-based biomarker discovery to diagnostic and clinical applications: A SOMAmer-based, streamlined multiplex proteomic assay. PLoS One. 2011;**6**(10):e26332. DOI: 10.1371/journal.pone.0026332

[183] Lollo B, Steele F, Gold L. Beyond antibodies: New affinity reagents to unlock the proteome. Proteomics. 2014;**14**(6):638-644. DOI: 10.1002/ pmic.201300187

[184] Mehan MR, Ayers D, Thirstrup D, Xiong W, Ostroff RM, Brody EN, et al. Protein signature of lung cancer tissues. PLoS One. 2012;**7**(4):e35157. DOI: 10.1371/journal.pone.0035157

[185] Müller J, Friedrich M, Becher T, Braunstein J, Kupper T, Berdel P, et al. Monitoring of plasma levels of activated protein C using a clinically applicable oligonucleotide-based enzyme capture assay. Journal of Thrombosis and Haemostasis. 2012;**10**(3):390-398. DOI: 10.1111/j.1538-7836.2012.04623.x

[186] Yan X, Song Y, Liu J, Zhou N, Zhang CL, He L, et al. Two-dimensional porphyrin-based covalent organic framework: A novel platform for sensitive epidermal growth factor receptor and living cancer cell detection. Biosensors & Bioelectronics. 2018;**5663**(18):30944-30948. DOI: 10.1016/j.bios.2018.11.047

[187] Song Y, Shi Y, Huang M, Wang W, Wang Y, Cheng J, et al. Bioinspired

engineering of multivalent aptamerfunctionalized nanointerface to enhance capture and release of circulating tumor cells. Angewandte Chemie International Edition. 2018;**131**:1-6. DOI: 1002/ anie.201809337

[188] Hong P, Li W, Li J. Applications of aptasensors in clinical diagnostics. Sensors. 2012;**12**(2):1181-1193. DOI: 10.3390/s120201181

[189] Bhat VG, Chavan P, Ojha S, Nair PK. Challenges in the laboratory diagnosis and management of dengue infections. The Open Microbiology Journal. 2015;**9**:33-37. DOI: 10.2174/1874285801509010033

[190] Tsai WY, Youn HH, Brites C, Tsai JJ, Tyson J, Pedroso C, et al. Distinguishing secondary dengue virus infection from Zika virus infection with previous dengue by a combination of 3 simple serological tests. Clinical Infectious Diseases. 2017;**65**(11):1829- 1836. DOI: 10.1093/cid/cix672

[191] Kim YJ, Kim HS, Chon JW, Kim DH, Hyeon JY, Seo KH. New colorimetric aptasensor for rapid on-site detection of *Campylobacter jejuni* and *Campylobacter coli* in chicken carcass samples. Analytica Chimica Acta. 2018;**1029**:78-85. DOI: 10.1016/j.aca.2018.04.059

[192] Labib M, Zamay AS, Kolovskaya OS, Reshetneva IT, Zamay GS, Kibbee RJ, et al. Aptamer-based impedimetric sensor for bacterial typing. Analytical Chemistry. 2012;**84**(19):8114-8117. DOI: 10.1021/ac302217u

[193] Yoon SY, Gee G, Hong KJ, Seo SH. Application of aptamers for assessment of vaccine efficacy. Clinical and Experimental Vaccine Research. 2017;**6**:160-163. DOI: 10.7774/cevr.2017.6.2.160

[194] WHO. Tuberculosis. 2018. Available from: https://www.who. int/news-room/fact-sheets/detail/ tuberculosis

[195] WHO. Global Tuberculosis Report 2015. DOI: 978-92-4-156450-2

[196] Elhassan MM, Elmekki MA, Osman AL, Hamid ME. Challenges in diagnosing tuberculosis in children: A comparative study from Sudan. International Journal of Infectious Diseases. 2016;**43**:25-29. DOI: 10.1016/j. ijid.2015.12.006

[197] Hilman BC. Pediatric tuberculosis: Problems in diagnosis and issues in management. The Journal of the Louisiana State Medical Society: Official organ of the Louisiana State Medical Society. 1998;**150**(12):601-610

[198] Racsa LD, Kraft CS, Olinger GG, Hensley LE. Viral hemorrhagic fever diagnostics. Clinical Infectious Diseases. 2016;**62**:214-219. DOI: 10.1093/cid/ civ792

[199] Miyazaki D, Shimizu D, Shimizu Y, Inoue Y, Inoue T, Higaki S, et al. Diagnostic efficacy of real-time PCR for ocular cytomegalovirus infections. Graefe's Archive for Clinical and Experimental Ophthalmology. 2018;**256**(12):2413-2420. DOI: 10.1007/ s00417-018-4111-9

[200] Nolan N, Halai UA, Regunath H, Smith LP, Rojas-Moreno C, Salzer W. Primary cytomegalovirus infection in immunocompetent adults in the United States—A case series. IDCases. 2017;**10**:123-126. DOI: 10.1016/j. idcr.2017.10.008

[201] O'Hara KM, Pontrelli G, Kunstel KL. An introduction to gastrointestinal tract CMV disease. Journal of the Academy of Physician Assistants. 2017;**30**:48-52. DOI: 10.1097/01. JAA.0000524712.40590.76

[202] Marty AM, Jahrling PB, Geisbert TW. Viral hemorrhagic fevers. Clinics in Laboratory Medicine. 2006;**26**(2): 345-386. DOI: 10.1016/j.cll.2006.05.001

[203] Behring K. Ueber das Zustandekommen der Diphtherie-Immunitüt und der Tetanus-Immunitüt bei Thieren. Dtsch Medizinische Wochenschrift. 1890;**16**:1113-1114. DOI: 10.1055/s-0029-1207589

[204] Edelman G. Antibody structure and molecular immunology. Annals of the New York Academy of Sciences. 1971;**190**:5-25

*Recent Advances in Analytical Chemistry*

2015. DOI: 978-92-4-156450-2

ijid.2015.12.006

civ792

[196] Elhassan MM, Elmekki MA, Osman AL, Hamid ME. Challenges in diagnosing tuberculosis in children: A comparative study from Sudan. International Journal of Infectious Diseases. 2016;**43**:25-29. DOI: 10.1016/j.

[195] WHO. Global Tuberculosis Report

[203] Behring K. Ueber das

10.1055/s-0029-1207589

1971;**190**:5-25

Zustandekommen der Diphtherie-Immunitüt und der Tetanus-Immunitüt bei Thieren. Dtsch Medizinische

Wochenschrift. 1890;**16**:1113-1114. DOI:

[204] Edelman G. Antibody structure and molecular immunology. Annals of the New York Academy of Sciences.

[197] Hilman BC. Pediatric tuberculosis: Problems in diagnosis and issues in management. The Journal of the Louisiana State Medical Society: Official organ of the Louisiana State Medical Society. 1998;**150**(12):601-610

[198] Racsa LD, Kraft CS, Olinger GG, Hensley LE. Viral hemorrhagic fever diagnostics. Clinical Infectious Diseases. 2016;**62**:214-219. DOI: 10.1093/cid/

[199] Miyazaki D, Shimizu D, Shimizu Y,

[200] Nolan N, Halai UA, Regunath H, Smith LP, Rojas-Moreno C, Salzer W. Primary cytomegalovirus infection in immunocompetent adults in the United States—A case series. IDCases. 2017;**10**:123-126. DOI: 10.1016/j.

[201] O'Hara KM, Pontrelli G, Kunstel KL. An introduction to gastrointestinal tract CMV disease. Journal of the Academy of Physician Assistants. 2017;**30**:48-52. DOI: 10.1097/01. JAA.0000524712.40590.76

[202] Marty AM, Jahrling PB, Geisbert TW. Viral hemorrhagic fevers. Clinics in Laboratory Medicine. 2006;**26**(2): 345-386. DOI: 10.1016/j.cll.2006.05.001

Inoue Y, Inoue T, Higaki S, et al. Diagnostic efficacy of real-time PCR for ocular cytomegalovirus infections. Graefe's Archive for Clinical and Experimental Ophthalmology. 2018;**256**(12):2413-2420. DOI: 10.1007/

s00417-018-4111-9

idcr.2017.10.008

**150**

## *Edited by Muharrem Ince and Olcay Kaplan Ince*

This book focuses on recent and future trends in analytical methods and provides an overview of analytical chemistry. As a comprehensive analytical chemistry book, it takes a broad view of the subject and integrates a wide variety of approaches. The book provides separation approaches and method validation, as well as recent developments and applications in analytical chemistry. It is written primarily for researchers in the fields of analytical chemistry, environmental chemistry, and applied chemistry. The aim of the book is to explain the subject, clarify important studies, and compare and develop new and groundbreaking applications. Written by leading experts in their respective areas, the book is highly recommended for professionals interested in analytical chemistry because it provides specific and comprehensive examples.

Published in London, UK © 2019 IntechOpen © romaset / iStock

Recent Advances in Analytical Chemistry

Recent Advances in

Analytical Chemistry

*Edited by Muharrem Ince and Olcay Kaplan Ince*