Silver-doped zirconium copper oxide nanohybrid for electrochemical identification of dihydroxybenzene isomers

Abstract

The transition metal oxide (TMO) nanohybrids are the optimal electrode materials for the electrochemical recognition of the dihydroxybenzene isomers (DHBIs). The DHBIs includes mainly catechol (CA), hydroquinone (HY), and resorcinol (RE). In the current study, Ag-ZrCuO nanohybrid is synthesized by the efficient combustion method. The crystal structure of the synthesized nanohybrid is analyzed using X-ray diffraction (XRD) analysis. The morphological features and elemental compositions are investigated through field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analysis. The presence of different vibrational modes is studied by Raman spectroscopy. As synthesized Ag-ZrCuO nanohybrid is deposited on the glassy carbon electrode (GCE) and electropolymerized with L-valine, resulting in poly-valine-reduced graphene oxide-silver doped zirconium oxide/copper oxide nanohybrid-GCE (PV-rGO-Ag-ZrCuO-GCE). The fabricated electrode exhibits superior electrochemical redox activity compared to the bare GCE, as confirmed by electrochemical impedance spectroscopy (EIS) and Tafel plots. The modified electrode is implemented for the electrochemical recognition of DHBIs by employing linear sweep voltammetry (LSV), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) techniques. The PV-rGO-Ag-ZrCuO-GCE detects CA, HY, and RE, with a limit of detection (LOD) determined to be 0.026 µM, 0.005 µM, and 0.082 µM. The corresponding linear ranges were 0.2–3.4 µM, 0.3–5.5 µM, and 0.2–1.4 µM. In addition, the prepared electrode shows excellent response for commercially available samples and the ternary mixture of DHBIs. The fabricated electrode displays a high percentage of repeatability, reproducibility, stability, and selectivity for the electrochemical detection of DHBIs. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.