Co3O4 nanocubes decorated single-walled carbon nanotubes for efficient electrochemical non-enzymatic glucose sensing

Abstract

In this study, we are presenting a novel hybrid nanostructure, composed of Co3O4 nanocubes adorned on single-walled carbon nanotubes (SWCNT) for electrochemical and non-enzymatic detection of glucose. The Co3O4/SWCNT nanocomposite was fabricated by simple hydrothermal method, followed by drop casting onto a glassy carbon electrode (GCE). The composition and grain size of as-fabricated nanocomposite was verified by X-ray diffraction, the morphology was studied by scanning electron microscopy and the functional groups were examined by Fourier transform infrared spectroscopy. The electrochemical and electrocatalytic behaviors of Co3O4/SWCNT based GC electrodes toward glucose were estimated by cyclic voltammograms, electrochemical impedance spectroscopy, and amperometric methods, respectively. This Co3O4/SWCNT/GCE biosensing device demonstrated higher electrocatalytic activity for the electro-oxidation of glucose in the alkaline media, which furthermore proved to be strongly dependent on NaOH concentration. Our Co3O4/SWCNT/GCE biosensor showed a linear response from 1 to 5 mM with a sensitivity of 96.92 µA mM−1 cm−1 and limit of detection of 0.25 µM. Besides, it showed higher selectivity (7–14 times) for glucose against various interfering species including dopamine, ascorbic acid, NaCl, urea and uric acid. Based on these findings, we can foretell potential field applications of this Co3O4/SWCNT/GCE fabricated biosensor for sensitive and selective non-enzymatic estimation of glucose.