Carbon-supported nickel/nickel oxide nanohybrid composite as a high-performance sensor for electrochemical non-enzymatic glucose detection

Abstract

Diabetes mellitus is considered a serious medical issue that is the leading cause of mortality worldwide. Hence, there is a huge demand for developing efficient, reliable, and inexpensive non-enzymatic glucose sensors that can rapidly and accurately monitor glucose levels in physiological fluids. Herein, we developed an efficient and robust Ni/NiO@C composite as an electrocatalyst, which is synthesized via a simple co-precipitation method followed by a controlled annealing treatment. The resulting Ni/NiO@C composite has a spherical structure, yielding the salient features of large surface area, high structural void porosity, accessible surface-active edges, and redox-active centers of Ni²⁺/Ni³⁺ which could effectively improve the electrocatalytic oxidation for the detection of glucose. The detailed investigation revealed the electrochemical oxidation of glucose situated at 0.48 V with a wide linear range over the concentration from 0.5 μM to 2.0 mM. Based on the calibration plot, the limit of detection (LOD) and sensitivity were calculated to be 0.061 μM, and 9.73 μA cm⁻² μM⁻¹, respectively. The designed sensor's electroanalytical performance was effectively validated for the investigation of target species in actual samples. This work offers insights into the synergistic electrocatalytic activity of precious metal and enzyme-free catalysts for use in clinical diagnostics for the analysis of glucose molecules.