Spectroscopic studies on the interaction of Hypocrellin B with AuTiO2 nanoparticles

The present work investigates the interaction of Hypocrellin B (HB) with AuTiO2 nanoparticles using absorption, cyclic voltammetry, fluorescence, time resolved and laser flash photolysis measurements. Broad absorption along with red-shift indicates the formation of charge-transfer complex between HB and AuTiO2 nanoparticles. The higher binding constant values obtained from absorption and fluorescence measurements envisage that the binding of HB with TiO2 was greatly enhanced by the surface modification with Au metal particles. The observed static type of fluorescence quenching was confirmed by life time measurements. Laser flash photolysis revealed that the electron transfer occurs from the excited HB to the conduction band of nanoparticles.