Study of Diazonium Salt Film Covalently Attached at the Surface of Carbon

The electrochemically induced functionalization of glassy carbon electrode by aryl groups was achieved by reduction of in situ generated diazonium cations in aqueous media. The barrier properties of the grafted layers were evaluated by cyclic voltammetry in the presence of electroactive redox probes such as Fe(CN) 6 3-/4- and Ru(NH3) 6 3+. The modified electrodes exhibited very slow electron transfer in compare tounmodified surfaces, by factors that varied with the redox systems. However, after scanning the modified electrode in 0.1 M KCl soulution from 0.9 to -1.1 V for 10 cycles, the modified electrodes exhibited much faster electron transfer kinetics. Once the monolayer is switched ON, it supports rapid electron exchange with redox systems, but not with dopamine, which requires adsorption to the electrode surfaces. A ”switching” electrode may have the potential to impact the field of molecular electronics, which is one of the more popular areas of nanotechnology

Keywords:

cyclic voltammetry , Electrochemical Modification , Conductance Switching , surface chemistry