Abstract: Photo-induced electron transfer between the adsorbed heme proteins and nanosized silver particles was studied by surface-enhanced Raman spectroscopy. The results show that the adsorbed microperoxidase and cytochrome c can be reduced under a continuous irradiation of 413 nm laser. The photo-induced reduction of heme proteins is ascribed to the excitation of free electrons in silver metal due to the surface plasmon absorption of the nanosized silver particles. The excited electrons are transferred into the affinity level of the adsorbed molecules, resulting in the reduction of the adsorbed molecules.

Key words: Photoinduced electron transfer, Microperoxidase, Cytochrome c, Silver particle