A novel non-enzymatic electrochemical sensor based on NiS/Co3S4@h-Ni NWs core-shell electrode for glucose detection in human serum

Abstract

To obtain a non-enzymatic electrochemical sensor with good performance such as sensitivity, selectivity, and stability, fine-tuning and rational design of the electrocatalytic material are essential. In this study, a novel catalyst (NiS/Co3S4@h-Ni NWs) with a hierarchical core-shell structure was synthesized in two steps to be used as a non-enzymatic electrode for glucose detection. First, hierarchical nickel nanowires, h-Ni NWs (the core), were prepared by the reduction of Ni2+ ions by hydrazine N2H4, and then the h-Ni NWs are covered with NiS/Co3S4 (the shell) by the hydrothermal method. The resulting NiS/Co3S4@h-Ni NWs showed a core-shell structure with abundant nanotides on the surface and good crystallinity. The prepared sensor exhibited two linearity ranges in the glucose concentration ranges of 0.001–6.57 mM and 6.57–13.32 mM with a sensitivity of 1171.9 μA mM−1 cm−2 and 316.5 μA mM−1.cm−2, respectively, and with a low detection limit of 0.13 μM (S/N = 3) due to its developed core-shell structure that provides excellent conductivity, an efficient mesoporous network, and suitable channels for rapid ion/electron transfer for electrocatalytic activity. In addition, the sensor also showed exceptional selectivity against coexistence interference, good long-term stability, reproducibility, and repeatability. All these excellent results show that the prepared NiS/Co3S4@h-Ni NWs catalyst can be a promising electrode material for glucose detection.