**3.9 Carbon black nanomaterials**

Since the discovery of carbon nanotubes, carbon-based nanomaterials being researched in various disciplines including electrochemistry. An old and cost-effective material recently called carbon black (CB) reinvented. CB has good electrical conductivity, dispersible in solvents, possibility of easy functionalization and has a large number of defect areas and fast electron transfer kinetics [113–116].

Previously, CB's main application in the electrochemical field was based on the design of sensors for analyte detection in fuel cell and gas phases for lithium and sodium batteries [117, 118]. However, until 2009, only a few CB-based electrochemical sensors were reported for analyte detection.

Among nanomaterials, CB demonstrated high potential in customizing all from the oldest carbon paste to glassy carbon and printed electrodes thanks to their fascinating electrochemical properties combined with cost effectiveness**.**

One of the main properties of CB is its ability to produce easily stable dispersions in a variety of solvents such as ethanol, acetonitrile, a mixture of dimethylformamide water [119], chitosan [120], or di hexadecylphosphate water solution [121], usually at a concentration of 1 mg/mL.

CB is widely used in the design of biosensors with a variety of biological recognition elements including enzymes, DNA and antibodies. The main potential of the enzyme combination with CB is based on the outstanding advantages this nanomaterial has in enhancing the biosensor sensitivity. CB can increase both conductivity and enzyme loading areas, thus causing increased signals and hence higher sensitivity. Some examples have shown that CB is a compatible substrate for the immobilization of enzymes in the design of amperometric biosensors [122].

Immunosensors have attracted great attention for specific, sensitive, costeffective and in-field analysis. Examples of CB-based immunosensors in unlabeled configuration have been reported in the literature [123, 124].

Alongside traditional bioreceptors such as enzymes, antibodies, and nucleic acids, CB also demonstrated the ability to improve their analytical performance by combining with alternative biological recognition elements or molecularly imprinted polymers [125].

Besides the biosensor application, CB was used in sensor design for both single analyte detection and multiple analysis, showing increased sensitivity thanks to its high conductivity, number of defective areas and surface area. Nowadays, most CB-based detection systems are mainly sensors, but in recent years there has been a sharp increase in publications in the development of enzymatic, immuno, and DNA biosensors [126].

CB is a new generation material due to its environmentally friendly properties in terms of costs and environmental impact.

The morphological properties of the synthesized carbon black by using commercial and waste polystyrene (PS) and high density polyethylene in different pyrolysis conditions were illustrated in **Figure 8** [16].

#### **Figure 8.**

*FE-SEM images of the carbon black obtained from: A commercial PS pyrolyzed at 500°C; b commercial PS pyrolyzed at 900°C; c waste PS pyrolyzed at 500°C; d waste PS pyrolyzed at 900°C; e high density polyethylene (HDPE) pyrolyzed at 500°C; f HDPE pyrolyzed at 900°C.*

**183**

*The Novel Nanomaterials Based Biosensors and Their Applications*

applications due to its physical and chemical properties [127].

composite electrodes prepared using nanodiamond [128].

Nanodiamonds (ND), a new member of the carbon nanoparticle class, has recently received much attention in drug delivery, bio-imaging, and biosensor

Nanodiamond (ND) is of great interest in various fields of material science due to its various functional groups. An electrochemical biosensor containing copper, nano-diamond (ND) and carbon nanotube (CNT) was built to detect the amino acids of Parkia Seeds (PS). Electrochemical reaction of PS was carried out with

The AFM and SEM characterization of nanocrystalline diamond (NCD) and

Nanomaterials provide high surface areas and a biocompatible environment for enzyme loading. In the last decade, research of magnetic particles has resulted in their use in a large number of nano-sensing devices, providing ease of separation in solution. Various iron magnetic nanoparticles (MNPs) have proven to be an excellent nanomaterial for electrochemical biosensing applications due to their electroconductivity, biocompatibility and ease of synthesis properties. They make important contributions to the development of electrochemical nanobiosensors. Functionalized magnetic nanoparticles can be directed by the external magnetic field to site-specific drug delivery targets. Iron and iron oxide nanoparticles have been studied as signal amplification elements in biosensing [131]. Among these materials, magnetite (Fe3O4), a Fe2+ and Fe3+ complex oxide, is one of the most studied super paramagnetic nanoparticles**.** It has unique mesoscopic mechanical and physical properties and has many potential applications in various fields such as cell separation [132] and microwave absorption [133]. Fe3O4 nanoparticles have been widely used for in vivo examination [134]. The direct binding of cholesterol oxidase to Fe3O4 magnetic nanoparticles was investigated and the kinetic behavior, stability and activity of bound cholesterol were investigated [135]. Due to its easy preparation process, low toxicity, strong superparamagnetism and good biocompatibility, Fe3O4 has recently been used in biosensors for glucose, ethanol and acetaminophen. Prepared biosensors showed fast response and high sensitivity with a wide linear range [136, 137]. Fe3O4 - Au nanoparticles, have been

*(a) AFM topographic images of NCD films and (b) SEM image of BDND film grown on a Si substrate.*

boron doped nanocrystalline diamond (BDND) were illustrated in **Figure 9**

*DOI: http://dx.doi.org/10.5772/intechopen.94930*

**3.10 Nanodiamonds**

respectively [129, 130].

**3.11 Magnetic nanoparticles**

**Figure 9.**
