**4. Nanobiotechnology in drug discovery and development**

The application of nanobiotechnology has an impact on diagnostics and drug delivery. Currently, researchers are starting to use nanotechnology in the field of drug discovery and development. Nanocrystals (QDs) and other nanoparticles (gold colloids, magnetic nanoparticles, nanobarcodes, nanobodies, dendrimers, fullerenes, and nanoshells) have unique advantages for the development of drug and its discovery i.e. QDs and magnetic nanoparticles are being used for barcoding of specific analytes which are key components of the bio-barcode assay, can be future alternative to the protein chain reaction [1].

The term "Nanomolecular diagnostics" is the use of nanobiotechnology at molecular level to diagnose and treat chronic diseases", extending the limits of molecular diagnostics to the nanoscale. The nanomolecular diagnostic field can meet the rigorous demands of the clinical laboratory and can be cost-effectiveness [6].

Nanoparticles have emerged as promising nanoplatforms for efficient diagnostics and therapeutics possessing characteristic properties at the nanometric scale. The feasible immobilization of specific ligands on the surface of biological site have become ideal candidates for molecularly sensitive detection, molecular imaging, and novel carriers for targeted drug and gene delivery, targeted photothermal therapy [6]. The nanoparticle in the form of nano-vesicle surrounded by a membrane or a layer holds convenient surface i.e. spherical, cylindrical, plate-like for molecular assembly of inorganic or polymeric materials and drug. The size and size distribution of nanoparticle becoming extremely critical and plays very significant role for penetration through a pore structure of a cellular membrane. The Biomarkers for occupying their distinguished color requires efficient fluorescent probes which depends upon the narrow distribution of average particle sizes. These narrow sizes particles emit a very wide range of wavelengths. The multifunctional nano particles core with several luminescent layers like magnetic nanoparticles can detect and manipulate the particles. Thus the Nanoparticles provides combine platform of biotechnology, nanotechnology and information technology facilitating molecular, biochemical and biological processes, e.g. genetics and pharmacogenomics.

The surface morphology of nanoparticles can be redesigned to reach at their target like blood brain barrier and dermal tight junctions more efficiently, overcoming the efficacy issues of drug on the physiological barriers. In case of malignant tumors Nanoparticles with leaky vasculature structure may penetrate the lesion. Nanoparticles may contain natural and synthetic polymer for coating an inorganic core of superparamagnetic materials. Some examples of nanoparticles as contrast agents in magnetic resonance for molecular diagnosis are given here [5].

#### **4.1 Gold nanoparticles**

Gold nanoparticles are the most typically used nanomaterial in diagnostics; they have many different uses as properly. They may be extensively utilized as a connecting factor and to construct biosensors to hit upon ailment DNA. Rather than a fluorescent molecule, a gold nanoparticle can be attached to an antibody and other molecules, consisting of DNA, can be brought to the nanoparticle to supply bar codes. The gold particles are very chemically reactive and make excellent catalysts at nanometer scale. Recently, gold nanostructures have found a very important

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**4.4 Nanochips**

**4.5 Microfluidics (lab-on-a chip)**

*Role of Nanobiotechnology in Drug Discovery, Development and Molecular Diagnostic*

role in a wide variety of applications, including bio-imaging, drug delivery, toxic gas detection, biosensors and to demonstrate multiphoton absorption-precipitated

Quantum dots (QDs) are regarded as a unique class of fluorescent labels, with unique optical properties such as high brightness and long-term colloidal and optical stability; these are suitable for optical imaging, drug delivery and optical tracking, fluorescence immunoassay and other medicinal applications. The unique optical property of QDs allows one to investigate the real-time dynamic events in living cells and such events include interaction between intracellular proteins, the mechanisms of intracellular signal transmission and cell growth. Some benefits and downsides have been investigated more suitable optical residences compared with natural dyes like incredible imaging outcomes using organic dyes, absorption of

Conjugation Nanoparticle-DNA protein hold great promise in biomedical applications. Many Diverse strategies have been developed to conjugate nanoparticles and DNA proteins to assemble and purify nanoparticle-protein link. First, stable and biocompatible nanoparticles are synthesized. Conjugation of the nanoparticle to the DNA protein is then achieved via two different approaches that do not require heavy chemical modifications or cloning, cysteine-gold covalent bonding, or electrostatic attachment of the nanoparticle to charged groups of the protein. Co-functionalization of the nanoparticle with PEG thiols is recommended to help protein folding. Finally, structural characterization is performed with circular dichroism, as this spectroscopy technique has proven to be effective at examining protein secondary structure in nanoparticle-protein conjugates. In general, functionalization of NPs with proteins such as antibodies can be achieved by direct chemical covalent conjugation or electrostatic interactions. The Semi-artificial conjugates of nucleic acids and proteins by both covalent coupling chemistry, or else through noncovalent biomolecular recognition systems, which include receptorligands of complementary nucleic acids for immunological detection assays [15].

The Nano Chip System by utilizing electronically enhanced hybridization of complementary DNA strands, integrates advanced microelectronics and molecular biology into a platform technology with broad commercial applications in the fields of genomic diagnostics and has achieved 100% accuracy in the detection of nanoparticle. This technique helps in investigating DNA sequences or the pairing of separated strands of DNA with complementary DNA strands of the acknowledged collection that act as probes. Currently, DNA chips is known as DNA microarray assays that employs the energy of a digital contemporary that separates DNA probes to unique web sites at the array based on charge and size, then test sample (blood) can be analyzed for identifying DNA sequences via hybridization with these probes [16].

Microfluidics is the modern science of fluids on the nanometer scale. The nanodiagnostics involve microfluidic or "lab on a chip" structures, in which the

*DOI: http://dx.doi.org/10.5772/intechopen.92796*

**4.2 The quantum dots for drug discovery**

numerous drug molecules for an extended time frame [15].

**4.3 Conjugates of nanoparticles and DNA protein**

luminescence (mail) [14].

role in a wide variety of applications, including bio-imaging, drug delivery, toxic gas detection, biosensors and to demonstrate multiphoton absorption-precipitated luminescence (mail) [14].
