▎ 摘　　要

A novel nitrite (NO2-) sensor was fabricated by electrodepositing phosphotungstic acid (PW12O403-) on chitosan (CHIT)-graphene nanocomposites modified cysteamine/gold (Au) electrode. Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy were used to study the CHIT-graphene nanocomposites and the PW12O403-/CHIT-graphene/cysteamine/Au electrode. Cyclic voltammograms and chronoamperometric were used to evaluate electrochemical and electrocatalytic properties of the PW12O403-/CHIT-graphene/cysteamine/Au electrode. Electrochemical results showed that the PW12O403-/CHIT-graphene/cysteamine/Au electrode exhibited good electrochemical behaviors and electrocatalytic performance toward the reduction of NO2-. Electrocatalytic performance can be ascribed to large specific surface area and good conductivity of the CHIT-graphene nanocomposites and good electrocatalytic activity of PW12O403-. The sensor showed quick amperometric response, low detection limit, wide linear range, high sensitivity, high stability, and good reproducibility. Analytical performance suggests that it is possible to be a potential candidate for routine NO2- analysis.