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

We report the first example of a glucose/H2O2 biofuel cell operating at 5 mM glucose under air at 37 degrees C in 0.14 M 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 O-2. 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 O-2. The bienzymatic catalysis involved GOx at both electrodes. The biofuel cell exhibits OCV of 450 mV and maximum power output of 30 mu W cm(-2) at 0.3 V in 5 mM glucose and 0.14 M NaCl at 37 degrees C. This represents a novel alternative to the use of copper oxidases in conventional glucose/O-2 biofuel cells for implantableapplications. (C) 2013 Elsevier B.V. All rights reserved.