Electrocatalytic oxidation of nitric oxide at multi-walled carbon nanotubes modified electrode

In 0.1 mol/l KH2PO4-NaOH buffer solution (pH 7.0) the multi-walled carbon nanotubes (MWNTs) modified electrode exhibits high stability and strong catalytic effect toward the electrochemical oxidation of nitric oxide (NO), Upon further modification with a thin film of nation which is capable of preventing interference from anions, especially nitrite, this modified electrode can be employed as a NO sensor in solution with fast response and high selectivity. The experimental conditions. Such as Supporting electrolyte and amounts of nafion, as well as scan rate have been optimized. The currents (measured by constant potential amperometry) increase linearly with the concentrations of NO in the range of 2 x 10(-7) - 1.5 x 10(4) mol/l. The calculated detection limit is 8.0 x 10(-8) mol/l. Moreover, the determination is free from the interference of nitrite and some biological substances. The experimental results show that NO might be adsorbed on the surface of electrode and then transfer electrons. (C) 2002 Elsevier Science B.V. All rights reserved.