title: A redox hydrogel protects hydrogenase from high-potential deactivation and oxygen damage.
abstract: Hydrogenases are nature's efficient catalysts for both the generation of energy via oxidation of molecular hydrogen and the production of hydrogen via the reduction of protons. However, their O2 sensitivity and deactivation at high potential limit their applications in practical devices, such as fuel cells. Here, we show that the integration of an O2-sensitive hydrogenase into a specifically designed viologen-based redox polymer protects the enzyme from O2 damage and high-potential deactivation. Electron transfer between the polymer-bound viologen moieties controls the potential applied to the active site of the hydrogenase and thus insulates the enzyme from excessive oxidative stress. Under catalytic turnover, electrons provided from the hydrogen oxidation reaction induce viologen-catalysed O2 reduction at the polymer surface, thus providing self-activated protection from O2. The advantages of this tandem protection are demonstrated using a single-compartment biofuel cell based on an O2-sensitive hydrogenase and H2/O2 mixed feed under anode-limiting conditions.
authors.affiliation: 1] Center for Electrochemical Sciences-Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany [2].
authors.forename: Nicolas
authors.initials: N
authors.lastname: Plumeré
authors.affiliation: 1] Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany [2].
authors.forename: Olaf
authors.initials: O
authors.lastname: Rüdiger
authors.affiliation: 1] Center for Electrochemical Sciences-Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany [2] Center for Electrochemical Sciences-Elektroanalytik &Sensorik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Alaa Alsheikh
authors.initials: AA
authors.lastname: Oughli
authors.affiliation: Center for Electrochemical Sciences-Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Rhodri
authors.initials: R
authors.lastname: Williams
authors.affiliation: Center for Electrochemical Sciences-Elektroanalytik &Sensorik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Jeevanthi
authors.initials: J
authors.lastname: Vivekananthan
authors.affiliation: Center for Electrochemical Sciences-Elektroanalytik &Sensorik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Pöller
authors.affiliation: Center for Electrochemical Sciences-Elektroanalytik &Sensorik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Wolfgang
authors.identifier: 0000000329165223
authors.initials: W
authors.lastname: Schuhmann
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lubitz
mesh_terms: D001665:Binding Sites; D001674:Bioelectric Energy Sources; D004579:Electron Transport; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D014755:Viologens / Q000494:pharmacology
chemical_list: D014755:Viologens; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006864:Hydrogenase; D010100:Oxygen