Fig. 3.
Protection and performance of the bioanode. Protection of DvMF-[NiFe] from O2 at the bioanode (a) and power output of the DvMF-[NiFe]/Mv-BOD-based biofuel cell (b) in 0.1 M phosphate buffer (pH 7.4). a: Chronoamperometry of a P(GMA-BA-PEGMA)-vio//P(N3MA-BA-GMA)-vio/DvMF-[NiFe] bioanode at an applied potential of +0.16 V (vs. standard hydrogen electrode) and in H2 breathing mode. The solution was purged with Ar (100%) or Ar/O2 (95%/5%). b Power curve showing absolute power P and absolute current values I for a H2/O2 biofuel cell comprising a P(GMA-BA-PEGMA)-vio//P(N3MA-BA-PEGMA)-vio/DvMF-[NiFe] bioanode and the Mv-BOx biocathode measured with stepped potential chronoamperometry and in breathing mode. Average values for P and I calculated from three independent experiments are shown; error bars represent standard deviation. Source data are provided as a Source Data file. The maximum power output was determined to be 260 µW at 0.7 V. The cell reveals an open circuit voltage of (1.13 ± 0.03) V. Nominal hydrogenase loading (absolute value per bioanode/normalized by the area of bioanode): 1.8 nmol/14.3 nmol cm−2. P(N3MA-BA-GMA)-vio poly(3-azido-propyl methacrylate-co-butyl acrylate-co-glycidyl methacrylate)-viologen, P(GMA-BA-PEGMA)-vio poly(glycidyl methacrylate-co-butyl acrylate-co-poly(ethylene glycol) methacrylate)-viologen, DvMF-[NiFe] [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F, Mv-BOx bilirubin oxidase from Myrothecium verrucaria