Enhanced photocurrent production by photosystem I with modified viologen derivatives

This paper describes the construction of a photogenerated electron transfer system based on photosystem I (PSI) and modified molecular wires. Gold electrode surfaces were functionalized with sodium 3-mercapto-1-propanesulfonate and the 2,2′-dimethyl-4,4′-bipyridine cation to form a self-assembled monolayer, which enabled the subsequent immobilization of PSI. A higher photocurrent was observed in the presence of sodium ascorbate as an electron donor under irradiation at 680nm. ► Molecular wire was prepared by stepwise alkylation of 2,2′-dimethyl-4,4′-bipridine. ► Oxidation potentials of the modified molecular wire shifted negatively. ► Modified gold electrode showed a higher current density than that of previous system.