Amperometric sensor for hydroxylamine based on hybrid nickel-cobalt hexacyanoferrate modified electrode

Hybrid nickel-cobalt hexacyanoferrate (NiCoHCF) particles were immobilized onto a glassy carbon electrode by cyclic voltammetry. Characterization of these particles by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electrochemistry revealed that NiCoHCF was a substitution-type hybrid hexacyanoferrate rather than a simple mixture system. As an important reducing agent, hydroxylamine could be electrocatalytically oxidized at the NiCoHCF modified electrode. The effects of the solution pH and the applied potential on the amperometric response of hydroxylamine were examined. Under optimum conditions, the catalytic peak current was proportional to the concentration of hydroxylamine in the range 2.0 × 10 ^-5-1.0 × 10^-2 mol/L with a detection limit of 2.3 × 10^-7 mol/L. Furthermore, detection results obtained with this sensor showed high sensitivity, fast response time, good stability and anti-interference ability.