Green synthesis of perovskite-type TbFeO3/CuO as a highly efficient modifier for electrochemical detection of methyldopa

In this study, TbFeO3/CuO nanocomposite was synthesized with a low-cost, simple and green method in the presence of Crataegus, Ribes and black tea which are acted as fuel or alkalizing agents. The scanning electron microscopy (SEM), and X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and vibrating-sample magnetometer were employed (VSM) for characterizing TbFeO3/CuO nanocomposite. Moreover, an electrochemical sensor based on a carbon paste electrode (CPE) modified by TbFeO3/CuO for quantitative detection of methyldopa (MD) was fabricated. The TbFeO3/CuO nanocomposite exhibited a good electrocatalytic signal towards oxidation of MD. The cyclic voltammetry (CV) confirmed that the MD oxidation at the TbFeO3/CuO/CPE follows an irreversible and diffusion-controlled mechanism. In addition, the MD oxidation peak current achieved by the differential pulse voltammetry (DPV) displayed a linear increase with its concentration at a range between 0.04 and 300 μM and limit of detection (LOD) of 0.009 μM was calculated for MD. Finally, it has been found that the newly developed electrode is very suitable for MD sensing as a result of benefits such as simplified operations, easy procurement, a wider linear range, and proper stability and selectivity. These analytical capabilities support the direct and rapid MD determination in biological and drug samples.