Development of an electrochemical sensor based on a barium-doped copper oxide anchored carbon black modified glassy carbon electrode for the detection of Metol

Abstract

In this study, Ba–CuO (barium-doped copper oxide) were synthesized by a hydrothermal method, then incorporated with CB (carbon black), and utilized as a superior composite Ba–CuO@CB to modify a GCE (glassy carbon electrode) for the detection of Metol (MTL). The prolonged consumption of Metol in industry and its discharge into river water and environmental water causes high impact, and it is very harmful for human health and biosphere. Therefore, it is crucial to determine Metol and methods to do so are in great demand. The constructed composite was further examined by physical characterization methods, including X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photon spectroscopy (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), and energy dispersive X-ray analysis (EDS). Moreover, the electrochemical detection process for MTL was scrutinized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Due to the outstanding electrocatalytic activity and extraordinary conductivity of Ba–CuO, the large surface area of CB, and the synergistic effect between Ba–CuO and CB, absorption- and diffusion-controlled layers play very important roles in the determination of MTL. The electrocatalytic activity of Ba–CuO@CB/GCE exhibits a remarkably low detection limit (0.3 μM), with a broad linear range of 0.01 to 1000 μM and good sensitivity (0.281 μA μM⁻¹ cm⁻²) towards the detection of MTL. Moreover, the outstanding recovery range of environmental samples further confirms the reliability and feasibility of Ba–CuO@CB/GCE for detecting the non-biodegradable organic pollutant Metol.