Cobalt-Based Ferrite Modified Carbon Nanotubes Fibers for Flexible and Disposable Microelectrode Toward Electrochemical Glucose Sensing

Glucose detection is critical in clinical health and the food industry, particularly in the diagnosis of blood sugar levels. Carbon-based fiber materials have recently featured prominently as non-enzymatic electrochemical glucose detectors. Herein, cobalt-based ferrite (CoFe₂O₄) in the form of nanoparticles has been successfully fabricated over the carbon nanotubes (CNTs) fiber via a simple hydrothermal process. Fabricated microelectrode (CoFe₂O₄@CNTs) was investigated as an electrocatalyst toward the non-enzymatic electrochemical glucose sensors. The structure and morphology of the modified fiber were studied by scanning electron microscopy including energy-dispersive X-ray spectroscopy. The electrochemical capability of the microelectrode was analyzed by using different electrochemical techniques including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy (EIS). The proposed sensors exhibited a superb sensitivity of 0.21 µAcm⁻² mM⁻¹, a good linear range from 1 to 9 mM, and a lower detection limit of 1.7 mM. Further investigation via EIS indicated the low charge transfer resistance as compared to the bare CNTs-based fiber. Outcomes revealed that the material can potentially prove promising for the disposable microelectrode toward electrochemical glucose sensing.