Effect of cobalt doping on NiSe2-based sensing electrode for non-enzymatic electrochemical ascorbic acid detection

Ascorbic acid is an essential antioxidant involved in redox homeostasis, immune response, and metabolic processes. The development of low-cost high accurate electrochemical sensors is critical to overcome conventional glass carbon electrodes (GCE). In this report, we report the first non-enzymatic electrochemical ascorbic acid sensors based on nickel diselenide (NiSe 2 ) grown on flexible carbon sheets using solvothermal process. Furthermore, the cobalt (Co) doping of various concentrations on NiSe 2 was synthesized and their electrochemical performances were evaluated. Structural and surface analyses using X-ray diffraction, field emission scanning electron microscope, and X-ray photoelectron spectroscopy confirm the successful formation and uniform distribution of Co on surface of NiSe 2 over the carbon sheet matrix. The electrochemical performance of the carbon sheet-based Co-doped NiSe 2 sensing electrode was evaluated using cyclic voltammetry and amperometric measurements, revealing efficient and selective redox properties. The sensor exhibits the linear response over the concentration range of 0.01 mM to 1 mM, with a rapid response of 2.6 s, and a low detection limit of 8.19 μM at an applied potential of 0.35 V with excellent selectivity. These results demonstrate the strong potential of Co doped NiSe 2 sensing electrode as low-cost, flexible and disposable sensing platforms for electrochemical ascorbic acid sensing.