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

Abstract

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.