Synthesis of Au nanoparticles dispersed on halloysite nanotubes-reduced graphene oxide nanosheets and their application for electrochemical sensing of nitrites

摘要

Nanocomposites of Au nanoparticles supported on natural halloysite nanotubes and graphene oxide ( HNTs-GO) were prepared and used for fabricating a novel nonenzymatic nitrite sensor. The structure and morphology of the Au-HNTs-GO nanohybrid film were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy ( EDS), scanning electron microscopy ( SEM) and transmission electron microscopy ( TEM). Electrochemical investigations were carried out by cyclic voltammetry and amperometry. The results indicate that the sensor possesses an excellent performance toward nitrites with two linear ranges: one from 0.1 mu M to 6.33 mM with a correlation coefficient of 0.9839 and a sensitivity of 23.1 mu A m(mol L-1)(-1) cm(-2), and another from 6.33 mM to 61.9 mM with a correlation coefficient of 0.9976 and a sensitivity of 86.5 mu A m( mol L-1)(-1) cm(-2). The detection limit of the sensor was 0.03 mu M with a signal-to-noise ratio of 3. In addition, the sensor could be applied in practical analysis and exhibits good reproducibility, long-term stability and anti-interference.