Abstract: The interaction between persimmon tannin and bovine serum albumin (BSA) and the mechanism of fluorescence quench were studied by fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy. The results showed that the fluorescence of BSA is quenched regularly by persimmon tannin. The binding constants and thermodynamic parameters of persimmon tannin with BSA are obtained at different temperatures. The hydrophobic interaction force and electrostatic force play a main role in the binding of persimmon tannin with BSA. The distances of binding site between persimmon tannin and BSA are also obtained according to the theory of Forster’s non-radiative energy transfer.

Key words: persimmon tannin, bovine serum albumin (BSA), interaction, fluorescence quench