Glucose oxidase and 1-butyl-3-methylimidazolium deposited by AC-electrophoresis on Pt as a glucose bioanode for biofuel cells

In this study, we have constructed a Pt/GOx-BMIM/PU electrode using alternating current electrophoretic deposition (AC-EPD) of glucose oxidase (GOx) in presence of 1-butyl-3-methylimidazolium [BMIM]+ and stabilized by a thin outer layer of polyurethane (PU). The Pt/GOx-BMIM electrode was characterized by optical microscopy, SEM and FT-IR. Optical microscopy and SEM showed the formation of thick and rough deposited films. The data from FT-IR illustrated the presence of both GOx and [BMIM]+ in the deposited film. Cyclic voltammetry showed that the presence of [BMIM]+ shift the starting potential of glucose electrooxidation by 420 mV toward negative values and led to a 3-fold increase in the current density. These two attributes make Pt/GOx-BMIM/PU a relevant bioanode for glucose/O2 biofuel cells. The Pt/GOx-BMIM/PU anode was connected to a Pt electrode as cathode and the non-compartmentalized cell was studied under air in phosphate buffer solution pH 7.4 containing 10 mM glucose. Under these conditions, the maximum power density reaches 36 μW cm−2. Furthermore, the stability over 3 weeks was shown to be pretty good due to the presence of the PU outer layer. Such electrodes have a great potential to be optimized, miniaturized to micro and nanoscale devices suitable as bioanodes for in vivo studies.