Polyferredoxin-based electrode materials

Electrochemical oxidation of the hydrosulfide cluster [Fe4S4(SH)(4)](2-) on gold, platinum or vitreous carbon in a methyl cyanide electrolyte leads to the growth of a conducting film. Spectroscopic and other evidence suggests that the film has cubane centres, predominately in the [4Fe4S](3+) oxidation state, which are linked by disulfide ligands to give an anionic array of [Fe4S4(S similar to)(4)](n-) units. X-ray data suggests some long-range order in the electrode material. The polyferredoxin binds redox active cations consistent with an anionic array.