Surface Au–H\nSpecies as Self-Generated Prosthetic\nGroups of a Formate Dehydrogenase-like Au Nanozyme to Engineer Multienzymatic\nActivities

Although the past decade has witnessed a rapid development\nof oxidoreductase-mimicking\nnanozymes, the mimicry of cofactors that play key roles in mediating\nelectron and proton transfer remains limited. This study explores\nhow surface Au–H species conjugated to Au nanoparticles (NPs)\nthat imitate formate dehydrogenase (FDH) can serve as cofactors, analogous\nto NADH in natural enzymes, offering diverse possibilities for FDH-mimicking\nAu nanozymes to mimic various enzymes. Once O<sub>2</sub> is present,\nAu–H species assist Au NPs to complete the on-demand H<sub>2</sub>O<sub>2</sub> generation for cascade reactions. Alternatively,\nwhen oxidizing organic molecules are introduced as substrates, Au–H\nspecies confer nitro reductase- and aldehyde reductase-like activities\non Au NPs under anaerobic conditions. Furthermore, similar to the\ndehydrogenase–NADH complex, Au NPs possessing Au–H species\nare gifted with esterase-like activity for ester hydrolysis. By revealing\nthat Au–H species are prosthetic groups for FDH-mimicking Au\nnanozymes, this work may inspire explorations into future self-generated\ncofactor mimics for nanozymes, thereby circumventing the need for\nexogenous cofactors.