Comparison of Electrocatalytic Performance of CuCo₂O₄ Nanorods and Nanospheres Decorated with Co₃S₄ Nanosheets for Electrochemical Sensing of Hydrogen Peroxide and Glucose in Human Serum

Abstract

Fabrication of reasonable nanoarchitectures for electroactive materials is regarded as one the important strategies for the enhancement of their electrocatalytic activity. Herein, CuCo2O4 nanorods and nanospheres were synthesized using a solvo-/hydrothermal method followed by annealing treatment. Then, Co3S4 nanosheets were grown on CuCo2O4 nanostructures by the electrochemical deposition method to form Co3S4/CuCo2O4 hybrid nanoarchitectures as active sensing materials for the determination of glucose and hydrogen peroxide. In comparison to the sphere-shaped Co3S4/CuCo2O4 nanocomposite, the CuCo2O4 nanorods anchored to Co3S4 nanosheets displayed superior electrocatalytic properties toward glucose oxidation and H2O2 reduction due to their high electrical conductivity and large surface area. The rod-like nanocomposite exhibited wide linear ranges (0.001–0.405 and 0.405–5.03 mM), high sensitivities (1062.50 and 512.50 μA mM–1 cm–2), low detection limit (2.1 μM), excellent selectivity, and long-term stability for glucose sensing. In addition, this sensor provided satisfactory results for determination of glucose in real biological samples. The as-proposed nanorod sensor also provided a high sensitivity (275 μA mM–1 cm–2) toward hydrogen peroxide reduction with a wide linear range of 0.001–4.03 mM and negligible interfering effects. These results suggest that the as-prepared electrocatalyst provides a promising sensing platform for the analysis of biological samples.