Facile fabrication of photoelectrochemical assemblies consisting of gold nanoparticles and a tris(2,2 '-bipyridine)ruthenium(II)-viologen linked thiol

Facile fabrication of a modified electrode with gold nanoparticles and a tr is (2,2 ' -bipyridine) ruthenium(II)-viologen linked thiol (RuVS) is descri bed. First, the gold nanoparticles (14 +/- 1 nm) were precipitated onto the gold electrode in an aqueous solution. Then, this electrode was immersed i nto a acetonitrile solution containing RuVS, to immobilize it via Au-S bond ing. Scanning electron micrographs show agglomeration and island formation of the gold particles on the electrode and 1-3 mum thickness of the deposit ion. In cyclic voltammetry, a redox couple due to one-electron reduction of the viologen moiety was clearly observed and its intensity increased with increasing the extent of deposition. The anodic photocurrent from the modif ied electrode ascribed to ruthenium-complex-sensitized redox cycles was cle arly observed and was more than 15-fold larger as compared with that of the flat electrode (without gold particles).