Magnesium doped silver ferrite nanohybrid for identification of dihydroxybenzene isomers

Abstract

The electrochemical identification of dihydroxybenzene isomers (DHBIs) using the magnetic transition metal oxide (TMO) nanohybrid is one of the best approaches for the study of electrochemical sensors. The DHBIs mainly include the catechol (CL), hydroquinone (HE), and resorcinol (RL). From this point of view, the ternary magnesium-doped silver ferrite (Mg-AgFe<inf>2</inf>O<inf>3</inf>) nanohybrid is prepared via the combustion approach, utilizing transition metal salts. The phase structure of the prepared nanohybrid is evaluated by X-ray diffraction (XRD). The surface characteristics were analyzed through Field emission scanning electron microscopy (FESEM). The elemental composition is confirmed by Energy dispersive X-ray (EDX) spectroscopy. The soft magnetic nature of the nanohybrid is evaluated by a Vibrating sample magnetometer (VSM). The prepared Mg-AgFe<inf>2</inf>O<inf>3</inf> nanohybrid is fabricated on the glassy carbon electrode (GCE). The electrode surface is electro-polymerized with glycine, which forms the poly-glycine-reduced graphene oxide-Mg-AgFe<inf>2</inf>O<inf>3</inf>-GCE (PG-rGO-Mg-AgFe<inf>2</inf>O<inf>3</inf>-GCE). The enhanced electrochemical activity of the prepared electrode for DHBI detection is attributed to the synergistic interaction among the magnetic Mg–AgFe<inf>2</inf>O<inf>3</inf> nanohybrid, reduced graphene oxide (rGO), and the PG diffusion layer. The electrode fabrication is examined through Electrochemical impedance spectroscopy (EIS). The fabricated GCE surface is studied for the electrochemical redox identification of DHBIs by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV) techniques. At the optimized pH, the modified electrode surface detects CL, HE, and RL at a limit of detection (LOD) and in the linear range of 0.039 µM (0.4–5.0 µM), 0.036 µM (0.3–3.5 µM), and 0.0086 µM (0.2–3.4 µM), respectively. The fabricated electrode simultaneously detects CL and RL is analyzed using the DPV method. The PG-rGO-Mg-AgFe<inf>2</inf>O<inf>3</inf>-GCE surface electrochemically identifies the CL, HE, and RL even in the presence of organic and inorganic interferents. Therefore, the modified electrode surface exhibits high specificity, sensitivity, repeatability, and reproducibility factors for electrochemical identification of the DHBIs. © 2025 Elsevier B.V.