Wiring of bilirubin oxidases with redox polymers on gas diffusion electrodes for increased stability of self-powered biofuel cells-based glucose sensing

A new redox polymer/bilirubin oxidase (BOD)-based gas diffusion electrode was designed to be implemented as the non-current and non-stability limiting biocathode in a glucose/O2 biofuel cell that acts as a self-powered glucose biosensor. For the proof-of-concept, a bioanode comprising the Os-complex modified redox polymer P(VI-co-AA)-[Os(bpy)2Cl]Cl and FAD-dependent glucose dehydrogenase to oxidize the analyte was used. In order to develop an optimal O2-reducing biocathode for the biofuel cell Mv-BOD as well as Bp-BOD and Mo-BOD have been tested in gas diffusion electrodes in direct electron transfer as well as in mediated electron transfer immobilized in the Os-complex modified redox polymer P(VI-co-AA)-[Os(diCl-bpy)2]Cl2. The resulting biofuel cell exhibits a glucose-dependent current and power output in the concentration region between 1 and 10 mM. To create a more realistic test environment, the performance and long-term stability of the biofuel cell-based self-powered glucose biosensor has been investigated in a flow-through cell design.The authors are grateful to Prof. Dr. R. Ludwig, BOKU - University of Natural Resources and Life Sciences, Vienna; for the provision of the FAD-GDH. We acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) in the framework of the SPP2240 (e-biotech) [445820469] and the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie MSCA-ITN "ImplantSens" [813006]