Development of a ternerry condunting composite (PPy/Au/CNT@Fe3O4) immobilized FRT/GOD bioanode for glucose/oxygen biofuel cell applications

Abstract

Enzymatic biofuel cells (EBFCs) are considered as a promising technology to sustain the requirements of miniaturized portable energy sources. Electrode materials being one of the substantial aspects of EBFCs have stimulated immense interest in research. A new platform made of nanocomposite, involving magnetic particles of iron oxide (Fe3O4), carbon nanotubes (CNT), gold nanoparticles (Au) and a conducting polymer polypyrrole (PPy), was used as the electrode support for the immobilization of glucose oxidase (GOD) which improves the bioelectrocatalysis of the enzyme towards oxidation of glucose. The structural and electrochemical characterization of the modified bioanode GCE/PPy/Au/CNT@Fe3O4/FRT/GOD was performed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV). The performance of the bioanode was evaluated with promising results showing the maximum current density of 6.01 mA cm−2 (0.22 V vs. Ag/AgCl) in 40 mM of glucose concentration at 0.38 V open circuit potential (OCV). The results suggested that PPy/Au/CNT@Fe3O4 nanocomposite significantly improve the surface area of the electrode and served as a suitable environment for enzyme immobilization, and established good electrical communication by facilitating electron transfer between enzymes and electrode surface. The as-synthesized composite has been inferred as a promising platform for improved bioelectrocatalysis owing to the excellent combination of superparamagnetism of Fe3O4 with good electrocatalytic properties of CNT, PPy, and Au nanoparticles. Thus PPy/Au/CNT@Fe3O4 nanocomposite can be considered as a prospective electrode material for developing better electrochemical biosensors and biofuel cell anode.