Density functional study of the cysteine adsorption on Au nanoparticles

The adsorption of the cysteine amino acid (H-SC H2C H-NH2-COOH) on the Au55 nanocluster is investigated through density functional theory calculations. Two isomers, with icosahedral and chiral geometries, of the Au55 nanocluster are used to calculate the adsorption energy of the cysteine on different facets of these isomers. Results involving the S(thiolate)-Au bonding show that the higher adsorption energies are obtained when the cysteine adsorbs on bridge sites of the facets containing Au atoms with the lowest coordination of the chiral Au55 cluster. These results are relevant to show the existence of enantiospecific adsorption on chiral gold clusters.