Gold Modification by Reduction of a Diazonium Salt Prepared from Aliphatic Diamine

Abstract

We report on the electrochemical reduction on gold electrode of diazonium salt prepared from lysine. For the first time, the covalent functionalization on gold of an alkyldiazonium salt is demonstrated and required diazotization of one amine group from lysine. The grafted organic films have been achieved and monitored using electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry (CV). Infrared absorption spectra (FTIR) and high resolution X-ray photoelectron spectroscopy measurements show that the organic film is successfully attached to the surface of the gold substrate. The major advantage and interesting of this procedure is that the diazonium cation is generated closely to the electrode surface. Moreover, the attached layers were found to be stable for two months after storage at room temperature as the recharacterization of modified gold surfaces provided the existence of organic film.This process could be useful for modifying various surfaces by different types of aliphatic amine.