Cytochrome c3-Langmuir–Blodgett film for hydrogen evolving device

Cytochrome c3 (cyt c3) is a mediator protein for hydrogenase (H2ase) in bacteria (Desulfovibrio sp.). Cyt c3 should play an important role in the enzymatic electrochemical energy conversion of electricity/hydrogen using hydrogenase. In this study, a monolayer film of cyt c3 was prepared to realize an electron mediating pathway by using the Langmuir–Blodgett (LB) technique with an amphiphilic peptide forming a complex with the protein molecule. The redox activity of the cyt c3 LB film was confirmed by spectroscopic analysis and cyclic voltammetry. Subsequently, the cyt c3 LB film deposited on a carbon graphite electrode was applied for the hydrogen evolution. At the applying potential, −350 mV (versus SHE), the cyt c3 LB film on the carbon graphite electrode mediated the electron transfer from electrode to hydrogenase in solution.