A single-walled carbon nanohorn-based miniature glucose/air biofuel cell for harvesting energy from soft drinks

We have demonstrated a miniature biofuel cell (BFC) with single-walled carbon nanohorn (SWNH)-modified carbon fiber microelectrodes (CFMEs) as the substrate for the first time. The bioanode was constructed by using glucose dehydrogenase (GDH) as the biocatalyst on SWNH-modified CFMEs, where a highly efficient and stably confined electrocatalyst for the oxidation of the NADH co-factor of GDH was beforehand immobilized. Similarly, an electrically contacted bilirubin oxidase (BOD)–SWNHs/CFME was prepared as the biocathode, which showed direct bioelectrocatalytic functions for the reduction of O2 to H2O. The maximum power output of the cell was 140 μW cm−2 at 0.51 V. Most interestingly, the present glucose/air BFC can directly harvest energy from different kinds of soft drinks, which could promise potential applications of the BFC as portable power sources.