Efficient Measurement and Validation of Nitrite with 5% Nafion-Coated with Low-Dimensional Fe2O3 Nanoparticle by Linear Sweep Voltammetry Approach

In this approach, low-dimensional Fe₂O₃ nanoparticles (NPs) synthesized using wet-chemical methods in an alkaline medium were comprehensively characterized using Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) before their application in nitrite sensing. These analyses detailed the nanoparticles morphology, optical properties, crystallinity, elemental composition, and electro-catalytic behavior. Fabricated with a 5% Nafion coating on a glassy carbon electrode (GCE), the Fe₂O₃ NPs facilitated efficient electrochemical oxidation of nitrite through two-electron transfer, enabling precise detection. The sensor demonstrated high sensitivity of 1.66 µAmM⁻¹cm⁻², reproducibility, and reliability, surpassing conventional detection methods. Nitrite concentration detection with a wide linear dynamic range (LDR) from 2.4 to 13.4 mM, displayed a clear linear current response with increasing applied potential. The sensor also exhibited a low limit of detection (LOD) of 8.6 × 10⁻⁶ M, limit of quantification (LOQ) of 26.1 × 10⁻⁶ M, enhanced sensitivity, selectivity, and stability, with consistent performance in repeated tests over 50 cycles using LSV. This work introduces an effective approach for nitrite detection using low-dimensional Fe₂O₃ nanostructures, validated through real environmental samples with RSD between 0.415% and 0.866%, whereas recoveries were recorded between 98% and 99.38%, providing a robust and sustainable solution for environmental monitoring.