Enhancing enzyme-free glucose detection with three-dimensional NiCo2O4 nanowire arrays wrapped with NiCo2O4 nanosheets

Incorporating a secondary metal and engineering heterogeneous nanostructures can significantly enhance the electrochemical performance of non-enzymatic glucose sensors. Herein, NiCo₂O₄ nanowire (NW) arrays were enveloped with NiCo₂O₄ nanosheets (NSs) using a simple hydrothermal method. NSs improved the electronic conductivity of NW arrays, while arrays prevented the aggregation of NSs, resulting in exceptional glucose sensing performance. In 0.1 mol·L⁻¹ NaOH electrolyte, this composite electrode demonstrated remarkable sensitivity (7641 µA·mmol⁻¹·L·cm⁻²), broad linear detection range (1 to 1250 µmol·L⁻¹), low detection limit (0.16 µmol·L⁻¹), and rapid response time (within 1 s), as well as excellent selectivity, reproducibility, and stability. Such a unique architecture of NiCo₂O₄ NW arrays enhanced the specific surface area of the composite material, facilitating the efficient electron transfer between copper foam and NiCo₂O₄ NSs. This work provides an economical and efficient approach for developing enzyme-free glucose sensing catalysts with superior electrochemical properties.