A sensor based on NiO/Fe2O3 modified GCE electrode for the detection of nitrite

Abstract

NiO/Fe₂O₃ modified glass carbon (GCE) electrode was prepared by electrodeposition of NiO nanoparticles on Fe₂O₃/GCE. The electrochemical characteristics of NiO/Fe₂O₃/GCE have been examined using cyclic voltammetry. The enhanced electrocatalytic activity of NiO/Fe₂O₃/GCE modified electrode for nitrite oxidation may be related to the synergistic effect of NiO and Fe₂O₃ nanoparticles, which may not only modify the electronic structure of the composite materials but also favor the increase of active sites in NiO/Fe2O3 and help to adsorb more active materials. To detect nitrite, the NiO/Fe₂O₃/GCE modified electrode was employed as an electrochemical sensor. There is a strong linear correlation between concentration and peak current (R = 0.9993) in the 5–500 μM range, and a detection limit of 0.05 μM (S/N = 3) was established. NiO/Fe₂O₃ sensors have excellent selectivity and stability as well. The sensor performs well analytically in determining nitrite in tap water, indicating that it has the possibility for efficient application in nitrite detection. This simple, low-cost, stable and highly sensitive nitrite electrochemical sensor provides a promising method for the detection of nitrite in practical samples.