Rectified photocurrent of biophodiode composed of cytochrome c/chlorophyll a hetero-structure

This photoelectrical rectifying property of biomolecular heterostructures is investigated in molecular scale. Cytochrome c and chlorophyll a were used as an electron acceptor and a sensitizer respectively in the molecular layer by mimicking photosynthesis. A self-assembled monolayer of cytochrome c was formed on Au surface, and then chlorophyll a was deposited onto the cytochrome c layer by Langmuir-Blodgett method. The formation of cytochrome c/chlorophyll a hetero-layers was confirmed by the surface plasmon resonance spectroscopy, and the surface was observed by the scanning tunneling microscopy. The rectifying property by the scanning-tunneling-spectroscopy based current-voltage characteristics was achieved in the cytochrome c/chlorophyll a hetero-layers. Thus, proposed hetero-layers functioned as rectifying property can be usefully applied for the development of molecular-scale bioelectronic devices.