Synthesis of Gold Nanoparticles and its Characterization Using Thiol Capping Agent

The study deals with the synthesis and characterization by the capping agent of thiol with gold nanoparticles, reduction by borohydride and interaction of S and Au, spectroscopic identification of gold nanoparticles. The interaction of thiol with gold nanoparticle in aqueous medium are proposed by employing UV-Vis, Fluorescence spectroscopy, and TEM analysis. TEM images will show capping agent of thiol with gold nanoparticles as distinct and spherical shape as compared to free colloidal gold nanoparticles. The study of capping agent such as BSA, Citrate, TGA, L-Cystein with gold nanoparticles were synthesized. It was found that TGA, L-Cysteine and BSA forms strong bond with Au-Nps surface due to replaces of Citrate ligand, illustrate that literature also articulate that Au-S bond is strong enough to replace Au-O bond that the Citrate ligand. The spectroscopic study of different thiol capping with Au-NPs and its optical spectra of Au-NPs and SPR band observed at 530 nm and size of Au-NPs ranges 30-50 nm. TEM Analysis of the Au-NPs size regime is in between in 10-100 nm shows good agreement with absorbance spectra.