NiO-Coated CuCo₂O₄ Nanoneedle Arrays on Carbon Cloth for Non-enzymatic Glucose Sensing

Transition-metal oxide nanocomposites with a core–shell structure exhibit excellent catalytic performance because of their large surface area and the synergetic effect resulting from their special structures. In this work, a two-step hydrothermal method was used to synthesize hierarchical CuCo2O4/NiO core–shell nanoneedle arrays (NNAs) on conductive carbon cloth (CC) as a self-supported electrode. The morphology and structure of CuCo2O4/NiO NNAs/CC were studied in detail by various microscopes and spectroscopes. The synthesized CuCo2O4/NiO NNAs exhibited excellent electrocatalytic properties toward glucose oxidation due to the hierarchical core–shell structure and the resulting synergetic effect. Therefore, CuCo2O4/NiO NNAs/CC showed excellent characteristics for glucose determination with high sensitivity (4140 μA mM–1 cm–2), broad linear range (0.5–6000 μM), and outstanding selectivity and stability. Moreover, the proposed sensor was evaluated to determine glucose in human serum samples with satisfactory recovery, indicating its potential practical application in quantitative analysis of blood glucose levels.