A Nernstian Biosupercapacitor.

We propose the very first "Nernstian biosupercapacitor", a biodevice based on only one redox polymer: poly(vinyl imidazole-co-allylamine)[Os(bpy) Cl], and two biocatalysts. At the bioanode PQQ-dependent glucose dehydrogenase reduces the Os moieties at the polymer to Os shifting the Nernst potential of the Os /Os redox couple to negative values. Concomitantly, at the biocathode the reduction of O by means of bilirubin oxidase embedded in the same redox polymer leads to the oxidation of Os to Os shifting the Nernst potential to higher values. Despite the use of just one redox polymer an open circuit voltage of more than 0.45 V was obtained during charging and the charge is stored in the redox polymer at both the bioanode and the biocathode. By connecting both electrodes via a predefined resistor a high power density is obtained for a short time exceeding the steady state power of a corresponding biofuel cell by a factor of 8.