Protection and Reactivation of the [NiFeSe] Hydrogenase from Desulfovibrio vulgaris Hildenborough under Oxidative Conditions

[Image: see text] We report on the fabrication of bioanodes for H(2) oxidation based on [NiFeSe] hydrogenase. The enzyme was electrically wired by means of a specifically designed low-potential viologen-modified polymer, which delivers benchmark H(2) oxidizing currents even under deactivating conditions owing to efficient protection against O(2) combined with a viologen-induced reactivation of the O(2) inhibited enzyme. Moreover, the viologen-modified polymer allows for electrochemical co-deposition of polymer and biocatalyst and, by this, for control of the film thickness. Protection and reactivation of the enzyme was demonstrated in thick and thin reaction layers.