An enzymatic glucose biofuel cell based on Au nano-electrode array

Herein a glucose biofuel cell capable of producing micro-watts power has been presented. The bioanode and the biocathode were fabricated using glucose oxidase and oxygen reducing laccase, respectively immobilized on a 4 × 4 Au nanotip pyramidal electrode array having a tip diameter of ~62 nm with an electroactive surface area of 0.04 cm². The power generating capability of the glucose biofuel cell was characterized in the presence of 5 mM, 10 mM and 20 mM glucose solution (pH 7) at 37° C to mimic the physiologic conditions. An open circuit voltage of 562.1 mV with a maximum power density of 112.21 μW cm^-2 at a cell voltage of 270.4 mV was delivered by the glucose biofuel cell operating in 20 mM glucose. The use for the 4 × 4 Au nanotip pyramidal electrode array provides a novel approach to improve the electroactive surface area for enzyme immobilization, in addition to enabling the electrochemical energy generation via direct electron transfer. The as-fabricated glucose biofuel cell has a great potential to be employed in powering low-power implantable bioelectronic devices.