Detection of nitric oxide with the iron (III) porphyrin doped nafion/glassy carbon electrode

Nitric oxide dissolved in buffer solutions has been detected by the electrochemical oxidation reaction on a glassy carbon (GC) electrode coated with Nafion film doped with various iron (III) porphyrins. The electrochemical detection was carried out by using different methods, such as normal pulse voltammetry (NPV), differential pulse voltammetry (DPV) and amperometry. All iron (III) porphyrins examined showed a catalytic activity for the electrolytic oxidation of nitric oxide. In the result, tetrakis-(pentafluorophengl) porphyrin iron (III) chloride (Fe(TPFPP)CI) showed the most prominent electrocatalytic activity. Amperometric detection of nitric oxide was successfully performed on the GC electrode coated with a Nafion film doped with Fe(TPFPP)CI. In the amperometry with an injection of NO solution, the lower detection limit was found to be about 10 nM.