Positively Charged Active Sites for the Adsorption of Five-Membered Heterocycles on Silver Colloids

The adsorption of isothiazole on silver colloids was studied by surface-enhanced Raman scattering (SERS) spectroscopy in comparison with other five-membered heterocycles. The experimental results coupled with those obtained by density functional theory calculations for molecule/metal complexes evidenced the presence of positively charged active sites on the surface of the silver nanoparticles, along with a close relation between ligand basicity and strong SERS effect.