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-propane-sulfonate 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 680 nm. (C) 2012 Elsevier B.V. All rights reserved.