Charge Transfer and Biocompatibility Aspects in Conducting Polymer-Based Enzymatic Biosensors and Biofuel Cells

Abstract

Charge transfer (CT) is a very important issue in the design of biosensors and biofuel cells. Some nanomaterials can be applied to facilitate the CT in these bioelectronics-based devices. In this review, we overview some CT mechanisms and/or pathways that are the most frequently established between redox enzymes and electrodes. Facilitation of indirect CT by the application of some nanomaterials is frequently applied in electrochemical enzymatic biosensors and biofuel cells. More sophisticated and still rather rarely observed is direct charge transfer (DCT), which is often addressed as direct electron transfer (DET), therefore, DCT/DET is also targeted and discussed in this review. The application of conducting polymers (CPs) for the immobilization of enzymes and facilitation of charge transfer during the design of biosensors and biofuel cells are overviewed. Significant attention is paid to various ways of synthesis and application of conducting polymers such as polyaniline, polypyrrole, polythiophene poly(3,4-ethylenedioxythiophene). Some DCT/DET mechanisms in CP-based sensors and biosensors are discussed, taking into account that not only charge transfer via electrons, but also charge transfer via holes can play a crucial role in the design of bioelectronics-based devices. Biocompatibility aspects of CPs, which provides important advantages essential for implantable bioelectronics, are discussed.

Affinity Sensors for the Diagnosis of COVID-19

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Dispersed Conducting Polymer Nanocomposites with Glucose Oxidase and Gold Nanoparticles for the Design of Enzymatic Glucose Biosensors

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“…[ 32 ]. These conjugated polymers also are characterized by excellent electrical properties, therefore, in some particular cases they may act as redox mediators and facilitate the transfer of electrons to the electrode [ 1 , 16 , 17 , 33 ]. The formation of charge carriers such as polarons, bipolarons, and solitons is leaded due to electrons addition or extraction from the delocalized π -boned polymer backbone [ 32 , 34 ].…”

“…During the enzymatic formation of π – π conjugated polymers, the monomer is ‘attacked’ by a radical cation induced by H 2 O 2 and this process is leading towards the polymerization reaction [ 32 , 36 ]. The π – π conjugated structures formed between the redox center of the enzyme and the electrode increase the efficiency of the charge transfer in this structure [ 10 , 16 , 17 , 33 ].…”

Laser-Induced Graphene-Based Enzymatic Biosensor for Glucose Detection

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