Hierarchical core-shell structured Ni₃S₂/NiMoO₄ nanowires: a high-performance and reusable electrochemical sensor for...

Designing highly active electrode is important for the fabrication of electrochemical sensing platforms, and core-shell nanostructures with large specific surface areas and ease of accessibility are effective probes for the detection of biomolecules. In this work, we report the development of hierarchical core-shell Ni3S2/NiMoO4 nanowires on a nickel foam substrate (Ni-Ni3S2/NiMoO4) as a non-noble metal catalyst electrode for the electrochemical oxidation of glucose in alkaline electrolyte. As an electrochemical sensor for glucose detection, the fabricated hierarchical Ni-Ni3S2/NiMoO4 core-shell nanowires display an enhanced catalytic response, a fast response time of 1 s with a limit of detection (LOD) of 0.055 μM (S/N = 3), and a higher sensitivity of 10.49 μA μM-1 cm-2. Unlike Ni3S2 or NiMoO4 electrodes, the observed superior catalytic activity towards glucose is mainly due to the promotional effect of NiMoO4 nanosheets on the Ni3S2 nanowires, which can increase the large active surface area and generate numerous active sites within and on the surface walls of the nanowire structures. The developed Ni-Ni3S2/NiMoO4 nanowire electrode can selectively detect glucose in the presence of other carbohydrates, such as fructose, sucrose, lactose, maltose, galactose, mannose, and xylose, indicating potential anti-interference properties. The Ni-Ni3S2/NiMoO4 nanowire electrode is highly stable for reuse and its practical application is demonstrated using real blood serum samples. These results demonstrate that hierarchical core-shell Ni3S2/NiMoO4 nanowires show potential for application in the development of low-cost applied glucose sensors.