▎ 摘　　要

Herein, iron oxide magnetic nanoparticles/graphene oxide decorated with acetic acid moieties (Fe3O4/GO/COOH) was synthesized and applied to fabricate a novel nitrite sensor in aqueous solutions (Fe3O4/GO/COOH/GC electrode). Acetic acid moieties were incorporated through nucleophilic reaction of chloroacetic acid with hydroxyl or epoxy groups on the surface of graphene oxide. The morphologies and compositions of fabricated nanomaterials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). The Electrochemical performance of Fe3O4/GO/COOH/GC electrode was evaluated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry techniques (DPV). The Fe3O4/GO/COOH/GC electrode was employed for the determination of nitrite in aqueous solutions. The DPV results showed a linear response of modified electrode with increasing concentration of nitrite in the range of 1-85 mu M and 90-600 mu M with a correlation coefficient of 0.99. The Fe3O4/GO/COOH/GC electrode displayed a considerable sensitivity towards nitrite detection with a detection limit of 0.37 mu M. Our results suggest the modified electrode as an easy to use and inexpensive candidate for analysis of nitrite concentrations, especially in real samples.