Electrochemical Properties of Modified Carbon Paste with Copper Hexacyanoferrate Film on Nitric Oxide Reduction

Abstract

Copper hexacyanoferate film was prepared electrochemically on carbon paste electrode and was tested for detection of nitric (II) oxide in comparison with unmodified electrodes. Modified electrode could be operated under physiological conditions (pH 7.5, 0.1 M phosphate buffer), with an operating potential of ﹣400 mV (vs. Ag/AgCl) in hydrodynamic amperometry. The amperometric response of the electrode showed good linearity up to 250 μM with a detection limit (3σ) of 8.32 μM. The relative standard deviation for the repeatability of measurements for 100 μM nitric (II) oxide was 4.1% (n = 10 measurements) and the corresponding reproducibility was 14% (n = 5 electrodes). The effect of investigated interferences (nitrite and nitrate ion) was not fatal and could be eliminated using the standard addition method. The modified electrode also seems promising to detect NO in car exhaust fumes.