Sensitive Electrochemical Sensor Modified by Hydroquinone Derivative and Magnesium Oxide Nanoparticles for Simultaneous Determination of Hydroxylamine and Phenol

Sensitive and selective detection of hydroxylamine (HX) in environmental samples, particularly in the presence of phenol, is of significant importance. Herein, we present an electrochemical sensor based on a carbon paste electrode (CPE) modified with magnesium oxide (MgO) nanoparticles (NPs) and 3,4-dihydroxy benzaldehyde, 2-(Phenyl) hydrazine (DHP), for the simultaneous determination of hydroxylamine and phenol. Employing voltammetric techniques, we investigated the electrocatalytic oxidation of hydroxylamine using the DHP/MgO NPs/CPE electrode. Under optimized conditions (pH = 7), the sensor exhibited a low detection limit of 1.7 μM and a wide linear range of 5.0–650.0 μM for hydroxylamine. The results revealed that the modified electrode significantly enhanced the oxidation activity of HX, resulting in a notable increase in current response compared to the bare electrode. The altered electrode demonstrated satisfactory stability, selectivity, and sensitivity for the detection of hydroxylamine. Furthermore, the developed electrode was successfully utilized for the determination of hydroxylamine in real drinking water samples. The satisfactory recoveries for HX (98.0–102.2%) indicated the high performance and reliable of the proposed method for the assessment of hydroxylamine in water samples. Distinct anodic peaks were observed in the differential pulse voltammetry responses of hydroxylamine and phenol at the surface of the proposed electrode, indicating the feasibility of simultaneous determination of these two compounds. In conclusion, the electrochemical sensor, using MgO NPs and DHP modification, detects hydroxylamine with precision and  enables environmental monitoring and water quality assessment.