Sea-urchin-structured NiCo2O4 decorated nitrogen-doped graphene for enhanced electrochemical detection of ascorbic acid

Developing high-performance electro-catalyst for detection of ascorbic acid is greatly desirable. A convenient and cost-effective route for the synthesis of sea-urchin-structured NiCo2O4 decorated nitrogen-doped graphene was demonstrated. The morphology, composition, and electrochemical properties of the obtained products were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and cyclic voltammetry. The electrocatalytic behaviors of sea-urchin-structured NiCo2O4 decorated nitrogen-doped gra-phene-modified glass carbon electrodes were investigated by cyclic voltammetry and chronoamperometry. The as-prepared electrode exhibited distinguished electrocatalytic oxidation of ascorbic acid. The linear response relationship for ascorbic acid was obtained ranging from 2.0 mu M to 6 mM with a rapid response time of less than 2 s and a low detection of the limit of 0.39 mu M (signal/noise = 3), which could be attributed to the high con-ductivity, high electroactivity for electrocatalytic oxidation of ascorbic acid, as well as high specific surface area of sea-urchin-structured NiCo2O4 decorated nitrogen-doped graphene. In addition, the modified electrode showed good anti-interference ability, long-term stability, and high reproducibility. The excellent electro-catalytic behavior of sea-urchin-structured NiCo2O4 decorated nitrogen-doped graphene may make it promising for applications in electrochemical analysis.