Photoinduced interaction of riboflavin dye with different reducing agents in aqueous and liposome media

The photoelectrochemical and spectral studies of riboflavin have been carried out in aqueous and phosphatidylcholine (PC) liposome media in presence of different reducing agents such as I-, Br-, Cl-, Fe2+, Fe(CN)6(4-) and Cu+. The results from both the studies support the photoinduced electron transfer from the reducing agent to the excited riboflavin dye. Moreover, a good correlation between photovoltages/Stern-Volmer quenching constants versus reduction potentials of the reducing agents also confirms the above electron transfer in the photoexcited state. An alternative method has been developed to determine the Stern-Volmer quenching constant.