Efficient Measurement and Validation of Nitrite with 5% Nafion‐Coated with Low‐Dimensional Fe ₂ O ₃ Nanoparticle by Linear Sweep Voltammetry Approach

Abstract 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 −1 cm −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.