Direct visible light activation of a surface cysteine-engineered [NiFe]-hydrogenase by silver nanoclusters

Abstract

Genetically engineering a cysteine (thiolate) close to the distal [4Fe–4S] cluster of a [NiFe]-hydrogenase creates a highly specific target for attachment of Ag nanoclusters templated in polymethyl acrylate, the resulting ‘hard-wired’ enzyme catalysing rapid hydrogen evolution by visible light. The rate is further enhanced by binding to metal oxide nanoparticles – results of investigations focusing on P-25 TiO₂ and including anatase TiO₂, rutile TiO₂, ZnO, SrTiO₃ and ZrO₂ leading to the proposal that these act as active or structural scaffolds to promote intra-assembly electron transfer.