Copper oxide and carbon nano-fragments modified glassy carbon electrode as selective electrochemical sensor for simultaneous determination of catechol and hydroquinone in real-life water samples

Abstract

The fabrication of robust sensors for the monitoring of emerging contaminants in real-life water samples has received much attention. In this study, copper oxide and carbon nano-fragment modified glassy carbon electrode (CuO-CNF/GCE) based electrochemical sensor was developed for the simultaneous monitoring of dihydroxybenzene isomers such as catechol (CC) and hydroquinone (HQ). The structural and morphological characterization of CuO-CNF/GCE was done by scanning electron microscopy - energy dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The electrochemical oxidation of HQ and CC was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CuO-CNF/GCE exhibited high current sensitivity for CC and HQ. The oxidation peak currents of CC at the CuO-CNF/GCE were linear function of concentration 0 μM to 150 μM, with detection limit of 2 μM (at a signal-to-noise ratio of 3) (R2 = 0.997) and the oxidation peak currents of HQ were linear function of concentration 3 μM to 80 μM, with 1 μM detection limit (S/N = 3) (R2 = 0.995). The CuO-CNF/GCE was successfully used for detecting the two dihydroxybenzene isomers in real-life water samples with high selectivity.