Sensitive detection of unsafe nitrite chemical based on GO@Fe2O3/Y2O3 nanocomposite by electrochemical approach for environmental assessment

Abstract

In this study, we quantified nitrite in phosphate buffer solution (PBS) at a pH of 8.00 using linear sweep voltammetry (LSV) under room conditions. The working electrodes (WE) were flat glassy carbon electrodes (GCEs) modified with a nanocomposite of graphene oxide, iron oxide, and yttrium oxide (GO@Fe2O3/Y2O3 NCs), fabricated using a 5 % Nafion conducting coating binder. The GO@Fe2O3/Y2O3 NCs were prepared by a solid-state chemical process and thoroughly analyzed using various techniques, including XRD, FTIR, FESEM, EDS, BET, HRTEM, EIS, and XPS, to examine their binding energy, surface area, crystallinity, structural integrity, functionality, and morphology. Electrochemical characteristics and detection capabilities of the modified electrodes were examined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The linear dynamic range (LDR) for nitrite detection, determined using LSV, was from 0.74 to 1.09 M. The sensor exhibited a sensitivity of 73.83966 µAmM−1cm−2, calculated from the slope of the calibration curve considering the electrode’s surface area. The lower limit of detection (LOD) was found to be 2.25 mM, and the limit of quantification (LOQ) was 7.50 mM. Additionally, we thoroughly investigated pH optimization, sensor-probe characteristics, stability, and reliability of the sensor under the same conditions. Validity tests conducted on the GO@Fe2O3/Y2O3 NCs/Nafion/GCE sensor probe demonstrated reliable and accurate performance in spike samples. This novel electrochemical sensor method shows promise for large-scale environmental chemical monitoring, aiming to enhance safety in environmental and healthcare sectors.