Preparation and General Properties of Chemically Modified Electrodes Based on Electrosynthesized Thin Polymeric Films Derived from Eugenol

Eugenol (4-allyl-2-methoxyphenol) was polymerized oxidatively by cyclic voltammetry at platinum and glassy carbon electrodes. It was found that at platinum the polymerization gives rise to a uniform, compact film which could serve as a permselective membrane for analytes of small molecular size. Applications of such films in selective detection of hydrogen peroxide and nitric monoxide were proposed. Monomer oxidation at glassy carbon resulted in less compact films. Interestingly, at higher potentials a porous structure containing large amount of unoxidized o-methoxyphenyl groups was created. This structure underwent electrochemical demethoxylation leading to the generation of redox active o-quinone functionalities when the modified electrode was cycled in acidic solution. A small amount of p- quinone functionalities was also generated. As could be anticipated the redox couples were capable of mediating electrochemical oxidation of ascorbic acid and NADH. Additionally polymeric eugenol-coated GC exhibited preconcentration capabilities towards dissolved metal cations. This effect was demonstrated on the electrochemical oxidation of preconcentrated Ce(III) and reduction of Cu(II).