CoO nanoparticles embedded in electrospun carbon nanofibers as free-standing nanocomposite electrodes as highly sensitive enzyme-free glucose biosensors

Numerous researches have been directed toward enzyme-free biosensors to alleviate the shortcomings encountered with enzymatic biosensors, in particular the intricate enzyme immobilization procedure. Herein, CoO/electrospun carbon nanofiber (ECNF) nanocomposites are successfully prepared to be employed as enzyme-free biosensors for diagnosis of glucose. Two parameters including the carbonization time and the amount of Cobalt(II) acetate tetrahydrate precursor are optimized, which are 5 h and 0.5 g, respectively. The 0.5 CoO/ECNF-5 h nanocomposite delivers superior sensitivity (475.72 μA·mM·cm), broad linear range (2–10 mM), and detection limit (LOD) less than 1 mM (0.82 Mm). In addition, the electrode shows excellent selectivity. The chronoamperometric analysis of 0.5 CoO/ECNF-5 h nanocomposite is performed by adding successively glucose analyte and interfering agents to the 0.1 M sodium hydroxide solution. No significant amperometric signal to the interfering agents including uric acid, ascorbic acid, and dopamine is delivered by this electrode, testifying the great selectivity of the electrode toward the diagnosis of target analyte (glucose) in spite of the existence of interfering species. Taking the aforementioned explanations into account, it can be concluded that the CoO/ECNF nanocomposite can be an appropriate free-stand electrode for high-performance enzyme-free glucose biosensor.