Formation and Electrochemical Evaluation of Polyaniline and Polypyrrole Nanocomposites Based on Glucose Oxidase and Gold Nanostructures.

Natalija German,Almira Ramanaviciene,Arunas Ramanavicius

doi:10.3390/polym12123026

Abstract

Nanocomposites based on two conducting polymers, polyaniline (PANI) and polypyrrole (Ppy), with embedded glucose oxidase (GOx) and 6 nm size gold nanoparticles (AuNPs(6nm)) or gold-nanoclusters formed from chloroaurate ions (AuCl4−), were synthesized by enzyme-assisted polymerization. Charge (electron) transfer in systems based on PANI/AuNPs(6nm)-GOx, PANI/AuNPs(AuCl4−)-GOx, Ppy/AuNPs(6nm)-GOx and Ppy/AuNPs(AuCl4−)-GOx nanocomposites was investigated. Cyclic voltammetry (CV)-based investigations showed that the reported polymer nanocomposites are able to facilitate electron transfer from enzyme to the graphite rod (GR) electrode. Significantly higher anodic current and well-defined red-ox peaks were observed at a scan rate of 0.10 V s−1. Logarithmic function of anodic current (log Ipa), which was determined by CV-based experiments performed with glucose, was proportional to the logarithmic function of a scan rate (log v) in the range of 0.699–2.48 mV s−1, and it indicates that diffusion-controlled electrochemical processes were limiting the kinetics of the analytical signal. The most efficient nanocomposite structure for the design of the reported glucose biosensor was based on two-day formed Ppy/AuNPs(AuCl4−)-GOx nanocomposites. GR/Ppy/AuNPs(AuCl4−)-GOx was characterized by the linear dependence of the analytical signal on glucose concentration in the range from 0.1 to 0.70 mmol L−1, the sensitivity of 4.31 mA mM cm−2, the limit of detection of 0.10 mmol L−1 and the half-life period of 19 days.

Highlights

The development of easy, fast and cheap technology for the determination of glucose is very important in clinical diagnostics, biotechnology, biofuel cells and food manufacturing [1,2,3,4,5,6,7,8,9,10].Another important branch, which recently appeared in the area of biotechnology, is the development of glucose-powered biofuel cells for possible electric current supply for implantable sensors and other bioelectronics devices [11]
The main aim of the present study was to evaluate some characteristics of a glucose biosensor based on polyaniline (PANI) and polypyrrole (Ppy), with embedded glucose oxidase (GOx) and 6 nm size AuNPs or gold-nanoclusters formed from chloroaurate ions (AuCl4 − ) (PANI/AuNPs(6nm) -GOx, PANI/AuNPs(AuCl4 − ) -GOx, Ppy/AuNPs(6nm) -GOx and Ppy/AuNPs(AuCl4 − ) -GOx) nanocomposites
PANI and Ppy nanocomposites with GOx and AuNPs were formed by enzyme-assisted synthesis of PANI and Ppy and were deposited on the surface of graphite rod (GR) electrodes

Summary

Introduction

The development of easy, fast and cheap technology for the determination of glucose is very important in clinical diagnostics, biotechnology, biofuel cells and food manufacturing [1,2,3,4,5,6,7,8,9,10] Another important branch, which recently appeared in the area of biotechnology, is the development of glucose-powered biofuel cells for possible electric current supply for implantable sensors and other bioelectronics devices [11]. These emerging research directions are requiring new advanced materials that are able to facilitate charge-transfer from red-ox enzymes towards electrodes [12,13]. The research related to the development of electrodes, discrimination membranes and immobilization methods, the application of new nanomaterials and of new electrochemically active compounds, which can improve the performance of glucose biosensors, is perennially performed [1,2,3,6,16]

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