Investigation of Interaction Between Casein Enzyme Hydrolysate and Biosynthesized Silver Nanoparticles by Spectroscopy

摘要

The interaction between silver nanoparticles and casein enzyme hydrolysate-Type I have been carried out by spectroscopic techniques (fluorescence, UV-Visible, and circular dichroism) at different temperatures (293, 303 and 313 K). UV-Vis spectroscopic data suggested the formation of ground state complex between casein enzyme hydrolysate and silver nanoparticles. The silver nanoparticles have a strong ability to quench the intrinsic fluorescence of casein enzyme hydrolysate by quenching mechanisms through dynamic quenching process. The number of binding sites 'n' and binding constants 'K' were determined at different temperatures based on fluorescence quenching. The thermodynamic parameters (Delta H, Delta G, and Delta S) of the interaction system were calculated at different temperatures and the results suggested that the binding process was spontaneous and the acting force between casein enzyme hydrolysate and silver nanoparticles were mainly hydrophobic forces and electrostatic interaction. Based on the Forster non-radiation energy transfer theory, the average binding distance between casein enzyme hydrolysate and silver nanoparticles was estimated to be 4.67 nm. Both synchronous fluorescence and circular dichroism spectra confirmed the interaction as mentioned which reflected in the conformational change of casein enzyme in presence of silver nanoparticles.