ABSTRACT
The interaction between water-soluble CdS and gelatin 5n aqueous solution was explored using fluorescence,infrared (IR)and UV-Vis spectra at pH 12.0 and different temperatures.Results show that the formed complex had a strong ability to quench the fluorescence launched from gelatin.The fluorescence quenching data were analvzed according to Lineweave-Burk double-reciprocal equation and the gelatin had reacted with CdS to form a complex.This kind of static fluorescence quenching goes with non-radiation energy transfer happening within single molecule According to Lineweave-Burk equation,K(285 K:1.07×10~4 L/mol;292 K:9 69×10~3 L/mol;299 K:8.06×10~3 L/mol),the formation constants of the compound at different temperatures and the thermodynamic parameters(△H=-14.18 kJ/mol;△G=-21.98/-22.28/-22.36 kJ/mol;△S=27.36/27.74/27.36 J/K·mol) at certain temperatures were obtained,indicating that the binding force between them is mainly the static in nature.The binding locality was an area of 4.09 nm away from tryptophan residue in gelatin based on F(o)rster's non-radiation energy transfer mechanism.The results provide information for exploring the chemical mechanism of interaction between nanoparticle and this kind of biological macromolecule.