A double-walled carbon nanotube-based glucose/H2O2 biofuel cell operating under physiological conditions.

Abstract: We report the first example of a glucose/H2O2 biofuel cell operating at 5mM glucose under air at 37°C in 0.14M NaCl. At a bienzymatic cathode, the direct wiring of horseradish peroxidase (HRP) achieves the electrocatalytic reduction of H2O2 concomitantly produced during the oxidation of glucose by glucose oxidase (GOx) in the presence of O2. At the bienzymatic anode, the indirect wiring of glucose oxidase achieves electrocatalytic glucose oxidation while catalase removes trace of H2O2 and, in combination with GOx, traces of O2. The bienzymatic catalysis involved GOx at both electrodes. The biofuel cell exhibits OCV of 450mV and maximum power output of 30μWcm−2 at 0.3V in 5mM glucose and 0.14M NaCl at 37°C. This represents a novel alternative to the use of copper oxidases in conventional glucose/O2 biofuel cells for implantable applications. [Copyright &y& Elsevier]