Preparation and characterization of a bioanode (GC/MnO2/PSS/Gph/Frt/GOx) for biofuel cell application

Abstract

In this study, a bioanode (GC/MnO2-PSS-Gph/Frt/GOx) was developed by depositing a manganese dioxide-polystyrene sulfonate-graphene (MnO2-PSS-Gph) composite containing ferritin (Frt) as mediator and glucose oxidase (GOx) as a catalytic enzyme on a glassy carbon (GC) electrode. The GOx oxidize the glucose to gluconolactone with the release of electrons. The composite was prepared by extending the Hummers method and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FTIR) spectroscopy. The electrochemical functioning of the fabricated bioanode was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge techniques. A maximum current density of 2.7 ± 0.2 mAcm−2 associated with the bioanode was observed at the scan rate of 100 mVs−1 in a potential range from −0.2 to 0.8 V having a glucose concentration of 40 mM. The surface concentration of GOx on the prepared bioelectrode was found to be 2.3 × 10−10 mol cm−2 and rate constant for the electron transfer was calculated to be 3.89 s−1.