Photocatalytic Hydrogen Production from Noncovalent Biohybrid Photosystem I/Pt Nanoparticle Complexes

A photocatalytic hyrdogen-evolving system based on intermolecular electron transfer between native Photosystem I (PSI) and electrostatically associated Pt nanoparticles is reported. Using cytochrome c(6) as the soluble mediator and ascorbate as the sacrificial electron donor, visible-light and induced production occurs for PSI/Pt nanoparicle biohybrids at a rate of 224 and H-2 (mg chlorophyll)(-1) h(-1) or 21.034 mol H-2 (mole PSI)(-1) h(-1). These results demonstrate that highly efficient photocatalysis of H-2 can be obtained for a self-assembled noncovalent complex between PSI and Pt nanoparticles, a molecular wire between the terminal acceptor of PSI, the [4Fe4S] cluster. F-B, and the nanoparticle is not required EPR characterization of the electron-transfer reactins in PSI/Pt nanoparticle biohybrids shows blocked electron transfer to flavodoxin the native acceptor protein of PSI, and presents evidence of low-temperature photogenerated electron transfer between PSI and the Pt nanoparticle. This work demonstrated a feasible strategy for linking molecular catalysts to PSI that takes advantage of electrostatic directed assembly to mimic acceptor protein binding.