Conductive Polymers and Their Nanocomposites: Application Features in Biosensors and Biofuel Cells

Abstract

Conductive polymers and their composites are excellent materials for coupling biological materials and electrodes in bioelectrochemical systems. It is assumed that their relevance and introduction to the field of bioelectrochemical devices will only grow due to their tunable conductivity, easy modification, and biocompatibility. This review analyzes the main trends and trends in the development of the methodology for the application of conductive polymers and their use in biosensors and biofuel elements, as well as describes their future prospects. Approaches to the synthesis of such materials and the peculiarities of obtaining their nanocomposites are presented. Special emphasis is placed on the features of the interfaces of such materials with biological objects.

Keywords: bioelectrochemistry; biosensors; conducting polymers; electrochemical sensors; microbial and enzymatic biofuel cells; nanocomposites; polymer-modified electrodes.

Figure 1

Advantages and disadvantages of conducting polymers for use in biosensors and biofuel cells.

Figure 2

Number of publications in the ScienceDirect database per year with conductive polymers and conductive polymer nanocomposite as keywords.

Figure 3

Structural forms of the most common conductive polymers.

Figure 4

General mechanism for the formation of conductive polymers. Reproduced with permission from ref. [28]. Copyright 2021 Elsevier Ltd.

Figure 5

Mechanism of chemical oxidative polymerization of polypyrrole. Reproduced with permission from ref. [40]. Copyright 2020 John Wiley & Sons Ltd.

Figure 6

(A–D) Synthesis of polyaniline using laccase. Reproduced with permission from ref. [42]. Copyright 2019 The Authors, Frontiers.

Figure 7

Typical schemes of interfacial polymerization (Lm—liquid phase containing monomers; S—solid phase; L—liquid phase) Reproduced with permission from ref. [43]. Copyright 2017 The Authors, Royal Society of Chemistry.

Figure 8

Scheme for the synthesis of porous poly(3,4-ethylenedioxythiophene) (PEDOT). (A) Design of porous PEDOT based on interfacial polymerization in a deep eutectic solvent system. (B) Some unique features of PEDOT porous material. Reproduced with permission from ref. [44]. Copyright 2023 The Authors, Wiley.

Figure 9

Mechanism of aniline electropolymerization. Reproduced with permission from ref. [50]. Copyright 2020 The Authors, IOP.

Figure 10

Methods for the synthesis of nanosized conductive polymers and nanocomposites. Reproduced with permission from ref. [34]. Copyright 2016 The Authors, MDPI.

Figure 11

Preparation scheme for PANI(HNTs) and PANI(HNTs)/rGO. Reproduced with permission from ref. [60]. Copyright 2022 John Wiley and Sons.

Figure 12

Scheme for the synthesis of polyaniline using soft templates. Reproduced with permission from ref. [61]. Copyright 2019 The Authors, American Chemical Society.

Figure 13

Number of experimental publications related to the development of biosensors based on “conductive polymers and carbon nanomaterials” composites. ScienceDirect database and keywords “conductive polymer-biosensor”.

Figure 14

Method of radical polymerization with atom transfer to create a nanostructured material. (a) Modification of multi-walled carbon nanotubes; (b) addition of α-bromoisobutyryl bromide; (c) synthesis of N-ethylpyrrole methacrylate monomer; (d) modification of the monomer with brominated carbon nanobooks; (e) polymerization without the addition of pyrrole; (f) copolymerization of the modified polymer with pyrrole. Reproduced with permission from ref. [66]. Copyright 2022 The Authors, Elsevier.

Figure 15

Nanostructured material based on carbon nanotubes and polypyrrole [66]. Copyright 2022 The Authors, Elsevier.

Figure 16

Three-dimensional porous composite based on poly(3,4-ethylenedioxythiophene) (PEDOT), poly(4-styrenesulfonate) (PSS), and graphene. Reproduced with permission from ref. [67]. Copyright 2020 Royal Society of Chemistry.

Figure 17

Composite based on carbon nanodots and polypyrrole. Reproduced with permission from ref. [68]. Copyright 2022 The Authors, Elsevier.

Figure 18

Microscopy of the starting materials and the resulting polymer: (A)—carbon nanodots; (B,C)—polypyrrole; (D)—hybrid. Reproduced with permission from ref. [68]. Copyright 2022 The Authors, Elsevier.

Figure 19

Fullerene-based ultrathin films. Reproduced with permission from ref. [71]. Copyright 2023 The Authors, American Chemical Society.

Figure 20

Bilayer membrane for lactamase immobilization. Reproduced with permission from ref. [73]. Copyright 2020 Elsevier.

Figure 21

(a)—SEM image of PANI; (b)—response of biosensor: reduction current vs. concentration of glucose. Reproduced with permission from ref. [90]. Copyright 2021 The Authors, Hindawi.

Figure 22

Scheme depicting the docking approach as compared to the hydrogel immobilization approach described here. Active redox protein is depicted in green, while inactive/denatured redox protein is depicted in gray. Reproduced with permission from ref. [100]. Copyright 2018 Royal Society of Chemistry.

Figure 23

(A) Schematic construction step of ITO/PDATT/cTnI-Ab/BSA electrochemical immunosensor for detection of cTnI. (B) Change in the orientation of the cTnI antibody molecules after their attachment to PDATT, backfilling with negatively charged BSA and binding to the cTnI protein. The green arrow depicts the flow of the [Fe(CN)₆]^3−/4− ions through the gaps between the upward-oriented antibody molecules. Reproduced with permission from ref. [132]. Copyright 2021 Elsevier.