Possible binding sites for biotin stabilized water soluble Ag nanoparticles: an experimental and theoretical study

The evolution of Ag nanoparticles by photochemical reduction method and the effect of biotin on their UV-Visible absorption spectrum were studied. Surface modification studies were carried out on chemically reduced Ag nanoparticles. ATR-FTIR studies showed that the biotin molecules bind with the surface of Ag nanoparticles through the oxygen of the carboxylate group. Theoretical calculations were carried out on the structure of the biotin and the silver complex of biotin (biotin(-)-Ag+) by optimizing their structures using density functional calculations with the B3LYP method using the LANL2DZ basis set. Theoretical calculations and experimental evidence favors a preferential binding of biotin molecule to Ag nanoparticles through the carboxylate group.