Efficient electrochemical sensing platform based on CeO2/NiCo2S4 acanthosphere-like microspheres and multi-walled carbon nanotubes composites toward detection of rutin

An efficient electrochemical sensor for rutin determination based on CeO 2 /NiCo 2 S 4 acanthosphere-like microspheres and multi-walled carbon nanotubes (MWCNTs) modified electrode was proposed. In this work, we design an acanthosphere-like CeO 2 /NiCo 2 S 4 heterojunction by an “in situ growth” method of hydrothermal process. Then MWCNTs were introduced into heterostructured microspheres to form composites of CeO 2 /NiCo 2 S 4 /MWCNTs. The morphology and elemental properties of the electrochemical materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The redox mechanism of rutin on the working electrode surface and the electrochemical properties were investigated by cyclic voltammetry (CV), chrono coulometry (CC) and electrochemical impedance spectroscopy (EIS). The results show that the CeO 2 /NiCo 2 S 4 /MWCNTs modified glassy carbon electrode exhibited excellent electric conductivity and electrocatalytic activity toward rutin, and increased effective working area. Under the optimized condition, the fabricated sensor expressed a good linear response for rutin analysis ranging from 0.5 to 65.4 μM with a low detectable limit of 4.37 × 10 -2 μM (S/N = 3). The electrochemical sensor shows good reproducibility and reliable stability, high sensitivity and selectivity, and has been successfully applied for rutin determination in orange juice and human urine samples.