Standard [NiFe]-hydrogenase from Desulfovibrio vulgaris Miyazaki F (DvMF-H₂ase) catalyzes the uptake and production of hydrogen (H₂) and is a promising biocatalyst for future energy devices. However, DvMF-H₂ase experiences oxidative inactivation under oxidative stress to generate Ni-A and Ni-B states. It takes a long time to reactivate the Ni-A state by chemical reduction, whereas the Ni-B state is quickly reactivated under reducing conditions. Oxidative inhibition limits the application of DvMF-H₂ase in practical devices. In this research, we constructed a mediated-electron-transfer system by co-immobilizing DvMF-H₂ase and a viologen redox polymer (VP) on electrodes. The system can avoid oxidative inactivation into the Ni-B state at high electrode potentials and rapidly reactivate the Ni-A state by electrochemical reduction of VP. H₂ oxidation and H⁺ reduction were realized by adjusting the pH from a thermodynamic viewpoint. Using carbon felt as a working-electrode material, high current densities—up to (200 ± 70) and −(100 ± 9) mA cm⁻³ for the H₂-oxidation and H⁺-reduction reactions, respectively—were attained.

宫崎骏（Desulfovibrio vulgaris Miyazaki F）的标准[NiFe]-加氢酶（Dv MF-H ₂酶）催化氢（H ₂）的吸收和产生，是未来能源设备的有前途的生物催化剂。但是，Dv MF-H ₂酶在氧化应激下会发生氧化失活，从而产生Ni-A和Ni-B态。通过化学还原使Ni-A状态重新活化需要很长时间，而在还原条件下Ni-B状态迅速被重新活化。氧化抑制作用限制了Dv MF-H ₂酶在实际设备中的应用。在这项研究中，我们通过协同作用构建了介导的电子转移系统-将Dv MF-H ₂酶和紫精氧化还原聚合物（VP）固定在电极上。该系统可以避免在高电极电势下将氧化失活成Ni-B态，并通过VP的电化学还原迅速使Ni-A态再活化。从热力学的观点出发，通过调节pH来实现H _2的氧化和H ^+的还原。使用碳毡作为工作电极材料，可获得高电流密度-分别达到H _2-氧化和H ^+-还原反应的（200±70）和-（100±9）mA cm ^-3。