Ferromagnetic iron oxide nanoparticles modified electrode as a sensor for determination of nitrite

A new method for the determination of nitrite was established based on ferromagnetic iron oxide nanoparticles (γ-Fe2O3) modified glassy carbon electrode (γ-Fe2O3/GCE). The morphology and structure of γ-Fe2O3 nanoparticles were characterized by scanning electron microscopy. In 0.2 mol/L HAc-NaAc (pH 4.8) buffer solution, the γ-Fe2O3/GCE showed a remarkable catalytic and enhancement effect on oxidation of the nitrite. The oxidation peak potential of nitrite shifted negatively from 1.06 V at bare GCE to 0.96 V at γ-Fe2O3/GCE, and the sensitivity increased ca 1.5 times. Under the optimized conditions, differential pulse voltammetry was used in the quantitative determination of nitrite and a linear dynamic range of 6.0×10-6 mol/L to 1.0×10-2 mol/L (R = 0.999) with a detection limit of 4.0×10-6 mol/L was obtained. The electrochemical mechanism was been obtained. Moreover, the sensor also exhibited high selectivity in the presence of the more possible interfering ions. This method has been used to determine the content of nitrite in real samples. The recovery was determined to be 101.0% to 104.8% by means of standard addition method. Copyright © 2016 American Scientific Publishers All rights reserved.