Efficient nucleophilic substitution in self-assembled monolayer of dithiol on gold

Many self-assembled monolayers of dithiols on gold feature terminal SH groups, the nucleophilic nature of which provides opportunities for covalent binding of electrophiles through sulfide linkages. This work describes an efficient coupling of dithiol derivative of 4,4'-dihydroxybiphenyl immobilized on Au surface with a mesylate ester present in the solution. The procedure did not require a glove box or any specialized equipment and provided a high surface concentration of the redox active product. The modified Au-SAM electrode was investigated electroanalytically.