Polythiophene-titanium oxide (PTH-TiO2) nanocomposite: As an electron transfer enhancer for biofuel cell anode construction

The determining factor of the performance of enzyme catalyzed biofuel cells (eBFCs) is the electrical connection between a redox active site of the enzyme and the electrode surface. Here, polythiophene-titanium oxide (PTH-TiO2) nanocomposite was synthesized through oxidative chemical polymerization. The PTH-TiO2 was used as a support material to immobilize the mediator ferritin (Frt) and the enzyme glucose oxidase (GOx) to develop a highly efficient and stable bioelectrode. The prepared bioanode showed effective electrical connection between the GOx and conductive support material via the Frt. The electrochemical analysis of PTH-TiO2/Frt/GOx bioanode evident that the use of PTH-TiO2 support material significantly improves the bioelectrocatalysis of glucose to gluconolactone via GOx. This was confirmed by the electrochemical analysis viz linear sweep voltammetry (LSV) and cyclic voltammetry (CV). The fitting equivalent circuit analysis measured charge transfer resistance (Ret = 93.48 ± 2.5 Ω), with the help of Nyquist plot obtained by performing electrochemical impedance spectroscopy (EIS). The morphological characterizations were confirmed the successful incorporation of PTH with TiO2. The current density obtained from PTH-TiO2/Frt/GOx bioelectrode was 7.8 ± 0.4 mA/cm2 at a scan rate of 100 mV/s in 30 mM glucose prepared in a phosphate buffer saline of pH 7.0.