NiO–Co₃O₄–rGO as a Multicomponent Transition Metal Oxide Nanocatalyst for Ultra‐level Detection of Nitrite in Beef and Tap Water Samples

Abstract

Abstract The detection of nitrite as a challenging compound in food industries has always been a necessity. To this purpose, herein, two transition metal oxide‐based nanocatalysts, NiO–Co 3 O 4 (NC) and its reduced graphene hybridized form, NiO–Co 3 O 4 –rGO (NCR), are synthesized by a hydrothermal method and characterized by X‐ray diffraction, Raman spectroscopy, scanning electron microscope (SEM) images, and energy dispersive X‐ray analysis (EDAX) mapping. The synthesized materials are exploited to modify a glassy carbon electrode and fabricate an effective sensor for nitrite detection in real samples through differential pulse voltammetry (DPV). NCR shows excellent sensitivity (40.44 µA per dec), very low limit of detection (20 × 10 ‐9 m ), significant accuracy, and good stability at the wide range of nitrite ions (100–500 × 10 ‐9 m ) in real samples.