The facile synthesis of a Co3O4–NiNP composite as an electrochemical non-enzymatic sensing platform for small chemical molecules

Abstract

In this paper, a new Co₃O₄–Ni nanocomposite-modified glassy carbon electrode (Co₃O₄–NiNPs/GCE) was successfully constructed and used to detect glucose and hydrogen peroxide (H₂O₂). The morphologies and structures of the Co₃O₄ and Co₃O₄–Ni nanocomposites were characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The construction process of the modified electrode was characterized via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Co₃O₄–NiNPs/GCE shows more excellent electrocatalytic activity for the detection of glucose and H₂O₂ compared with Co₃O₄/GCE and NiNPs/GCE. The amperometric i–t method was used for the quantitative analysis of glucose and H₂O₂. The plots of current difference versus concentration of glucose and H₂O₂ were linear in the range of 0.3–550 μM and 0.5–89 μM, respectively. The corresponding limits of detection (LODs) were 0.086 μM and 0.23 μM for glucose and H₂O₂, respectively. This recommended sensor was successfully applied for the quantitative analysis of glucose in fruit and H₂O₂ in water samples.