Immobilized glucose oxidase biofuel cell anode by MWCNTs, ferrocene, and polyethylenimine: Electrochemical performance

Abstract

AbstractFerrocene‐functionalized polyethylenimine and multiwalled carbon nanotubes were attached covalently by glutaraldehyde onto a carbon cloth to develop an immobilized enzyme (glucose oxidase) electrode for biofuel cell applications. Developed enzymatic anode was characterized by electrochemical methods to determine electrochemical performance. Anodic open‐circuit potential was measured as within 0–20 mV range. Cyclic voltammetry showed anodic peak for glucose oxidation around 400–600 mV (vs. sat. Ag/AgCl) varying with scan rate. An enzyme fuel cell with 2.5 mg/cm2 glucose oxidase‐loaded bioanode and 0.70 mg/cm2 Pt‐loaded cathode attached to Nafion™ 115 membrane has provided around 2.5 mA/cm2 current density at short‐circuit conditions. Enzymatic kinetic parameters of prepared anode were determined by electrochemical methods that surprisingly indicated less KM (i.e., better substrate affinity) than that of determined by conventional enzymatic methods. Enzymatic stability determined by electrochemical methods moreover indicated longer enzyme half‐life.