▎ 摘　　要

Although non-enzymatic electrochemical methods are advantageous for the detection of nitrite, a highly toxic pollutant, improved sensitivity is required for practical applications. Herein, a graphene oxide?polyaniline?Au nanoparticles (GO-PANI-AuNPs) nanocomposite prepared by a hydrothermal synthesis method was used to fabricate a novel electrochemical nitrite sensor. Structural and morphological characterisation of the nanocomposite using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy revealed that PANI formed a network structure on the GO surface and that a large amount of AuNPs were uniformly connected to the active sites of GO-PANI. Electrochemical investigations showed that the fabricated GO-PANI-AuNPs sensor exhibited excellent catalytic performance for the oxidation of nitrite. The sensor showed good selectivity for nitrite with linear ranges of 0.5 ?M?0.24 mM and 0.24 mM?2.58 mM and a detection limit of 0.17 ?M (signal-to-noise ratio of 3). This developed sensor was successfully applied to the detection of nitrite ions in tap water and sewage, and the recovery rate was 97%?105%. Therefore, the GO-PANIAuNPs nanocomposite offers a reliable electrochemical strategy for the detection of NO2?, which has important theoretical and practical significance for environmental monitoring applications.