and electrical characteristics that are superior to those of pure Pt NPs. This composite

may be used to print high-resolution 3D structures. Thus, the fabrication of future 3D

wearable bioelectronics with improved mechanical and electrical characteristics will be

possible in the future. Because of their enormous surface area, Pt NPs-decorated

Si composites have the potential to provide cathodal charge storage capacities of

B50 mCcm², which are comparable to those of strongly doped organic electrode coatings.

Aside from providing superior catalytic performance over hydrogen peroxide, Pt NPs

significantly improve the current density and detection sensitivity of graphene-based

glutamate and glucose sensors [40].

In another study, to monitor the intracellular action potentials in excitable cells such as

neurons and cardiomyocytes, Au-based nano-pillar with a mushroom-shaped have also

been demonstrated to be capable of recording subthreshold synaptic activity and action

potentials in vitro with minimal invasiveness for days at a time, which is 50 times longer

than the typical patch-clamp techniques [41]. Researchers discovered that mushroom-

shaped Au micro-electrodes significantly improved membrane engulfment, which is

advantageous for their application because it results in the formation of high resistance

seals between the interfaced cell and the electrodes [42].

1.4.4 Bioelectronics with Nanocarbons

Nanocarbons like graphene and carbon nanotubes (CNTs) are valued in bioelectronics due

to their exceptional chemical stability, biocompatibility, recyclability, great mechanical

flexibility, a huge surface area, and a broad electro-mechanical range. Nanocarbons are

used in the fabrication of fiber-like probes for biomedical applications. Energy storage and

electrochemical sensing are examples of electrochemical technologies using these carbon

materials. In addition, carbon microelectrodes with a conductive coating have been used for

high-resolution measurements. With an increase in synaptic activity as well as in vesicles,

oxidation of carbon fiber in a cell or near a cell can also take place [28,43].

1.4.5 Bioelectronics with Organic Conductors

Making conducting materials that are both very flexible and mechanically robust is one of

the most challenging difficulties faced by researchers working on bioelectronics in the past

few decades. In comparison to the majority of inorganic conducting materials currently on

the market, organic conducting materials, such as conjugated polymers and hydrogels,

have the potential to be more biocompatible and easier to manufacture [44,45]. The con­

ductive polymers have been discovered for use in flexible electronics, and only a few have

been used for bioelectronics applications. Current research is mostly focused on three

materials, namely poly(3,4-ethylenedioxythiophene)poly(styrene sulfonate) (PEDOT-PSS),

polypyrrole (PPy), and polyaniline (PANI) in particular [46].

The development of synthetic approaches to increase the purity of PEDOT-PSS is im­

portant due to the risk that additives may impair the material homogeneity and introduce

the possibility of cytotoxicity. Because of the collapse of the fibrillary structure, which

decreases the conductivity of pure PEDOT-PSS hydrogels when synthesized under normal

conditions, it is difficult to obtain a consistent result in the laboratory (Figure 1.6a) [46].

Purified PEDOT-PSS may be produced using a process developed by Luet al. [46] that

maintains the desired features like the material’s stability, flexibility, and conductivity.

Adding DMSO to aqueous PEDOT-PSS, they were able to form interconnected and pure

PEDOT-PSS nano-fibrils (Figure 1.6b). At the end of the process, a dry phase-separated

Introduction to Bioelectronics

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