Dispersed gold nanoparticles on NiO coated with polypyrrole for non-enzymic amperometric sensing of glucose

Abstract

A highly sensitive and selective non-enzymatic glucose sensor based on loading Au on NiO nanoparticles which were encapsulated by polypyrrole (named as NiO@PPy/Au) modified glassy carbon electrode (GCE) was constructed. Morphology images of the synthesized samples were characterized by transmission electron microscopy and the nanoparticles were characterized by Fourier transform infrared spectroscopy, UV-vis spectrometry and X-ray diffraction. Electrochemical behaviors of glucose at the NiO@PPy/Au/GCE were investigated by cyclic voltammetry and amperometry, and the modified electrode showed excellent electrochemical activity toward the oxidation of glucose. Under the optimum conditions, the calibration curve for glucose determination was linear in the range of 0.5 μM to 1.7 mM and a fast response time (<4 s), high sensitivity of 802.9 μA mM⁻¹ cm⁻² and a low detection limit (S/N = 3) of 0.15 μM were obtained. In addition, the proposed sensor was successfully applied to analyze the glucose level in human blood serum samples.