Electrocatalytic oxidation of nitric oxide at indium hexacyanoferrate film-modified electrodes

The electrocatalytic oxidation of nitric oxide (NO) by indium (III) hexacyanoferrate (III) films has been studied. These films are electrodeposited onto glassy carbon electrodes through potential cycling in acidic solutions containing a potassium electrolyte, indium (III), and potassium hexacyanoferrate. The resulting modified electrodes exhibit a reversible redox response ascribed to the oxidation/reduction of iron atoms presents in the electrodeposited film. The films have a potent and persistent electrocatalytic activity towards NO oxidation at neutral pH. The electrocatalytic oxidation of NO takes place at potentials around +0.75 V which represents a moderate diminution in the overpotential. In addition, interferences due to the presence of nitrate and nitrite have been significantly reduced. According to these results, the described modified electrodes have been used as sensors for the determination of NO generated by decomposition of a typical NO-donor, such as S-nitroso- N -acetyl- d, l -penicillamine (SNAP).