Electrochemical detection of 4-nitrophenol with Y₂O₃@MgO-GO modified electrochemical sensor by linear sweep voltammetry

In this study, a glassy carbon electrode (GCE) coated with binary metal oxides, specifically yttrium oxide (Y₂O₃) and magnesium oxide (MgO), along with a precursor graphene oxide (GO) nanocomposite (NCs) (Y₂O₃@MgO/GO/NCs/GCE), was fabricated to improve the accuracy of 4-nitrophenol (4-NP) detection. The hybrid NCs were synthesized via a solid-state method and comprehensively characterized using UV/visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), powder X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analyses to determine its morphology, functional groups, crystalline structure, and surface area. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used to investigate the electrochemical performance, demonstrating the selective and efficient detection of 4-NP with the Y₂O₃@MgO/GO/NCs/Nafion/GCE sensor. The concentration range of 4-NP is between 1 and 80 μM, with a lower limit of detection (LOD) of 0.43 μM with higher sensitivity (34.7 μAμM⁻¹ mm⁻²). The electrochemical method was established for the detection of 4-NP in real environmental samples (river, lake, industrial, and sea waters), with high reliability, showing recoveries between 95.19 % and 98.76 %. The sensor design provides the advantages of simple fabrication, rapid analytical response time, high sensitivity, and satisfactory reproducibility. This study serves as the first demonstration of a new approach using binary metal/oxide hybrid nanocomposites for the sensing of carcinogenic compounds and thus has led to an advancement in environmental safety and public care toward the environment.