Advanced binder-free electrode based on cuco₂o₄ nanowires coated with polypyrrole layer as a high-performance nonenzymatic glucose sensing platform

In this work, the CuCo₂O₄ nanowires (CuCo₂O₄ NWs) were grown on carbon cloth electrode (CCE) and then coated with polypyrrole (pPy) layer (CuCo₂O₄ NWs-pPy@CCE). The morphology and structure characterization of as-prepared CuCo₂O₄ NWs-pPy@CCE were carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), and transmission electron microscope (TEM). The CuCo₂O₄ NWs-pPy@CCE was applied directly as an electrocatalyst toward nonenzymatic glucose oxidation. Due to the advantages of this 3D structure, it offer high availability to the analyte/electrolyte, abundant electrochemical-active sites, and high stability and conductivity. As a glucose sensor, the CuCo₂O₄ NWs-pPy@CCE shows wide linear range (0.01 to 21.3 mM), excellent sensitivity (4.41 µA µM⁻¹ cm⁻² ), good selectivity, low detection limit (0.2 µM), and rapid response time (<1 s) toward glucose detection. Furthermore, the designed sensor shows a great ability in detection of glucose in biological real samples.