Immobilization of Aryl and Alkynyl Groups onto Glassy Carbon Surfaces by Electrochemical Reduction of Iodonium Salts

A new versatile method has been developed for the electrochemically assisted grafting of carbon materials. The approach is based on the reduction of iodonium salts and allows the immobilization not only of aryl groups, such as phenyl or nitrophenyl, but also of alkynyl groups under mild conditions. In particular, the immobilization of alkynyl groups is important because such grafting cannot be accomplished using any other known reductive procedure. The electrochemical properties of the grafted surfaces with estimated coverages of (4−6) × 10-10 mol cm-2 are investigated against the ferrocene and Fe(CN)6 3- solution probes. The analysis of the surfaces is carried out by means of cyclic voltammetry and X-ray photoelectron spectroscopy.