ABSTRACT
A two-step and fast electrochemical approach for the synthesis of CdSe@ Cu2Se core-shell quantum dots is applied in the mixture of ethylene glycol-based deep eutectic solvent and 5% water as a green media to modify the graphene film-coated glassy carbon electrode for fabricating a sensitive surface. The quantum dots particles were systematically characterized by Energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, UV-visible and Fluorescence emission spectroscopy, transmission electron microscopy (TEM) and cyclic voltammetry (CV) techniques. The results show the existence of a second-order chemical reaction after occurring the electron transfer reaction for pyrazinamide. The CdSe@Cu2Se modified graphene-coated glassy carbon electrode was successfully used for the determination of pyrazinamide by differential pulse voltammetry method under the optimized conditions (pH = 2) in the range of 0.4-10 µM with a corresponding detection limit of 0.37 µM. The proposed modified sensor demonstrated high selectivity, reproducibility, stability in the pharmaceutical tablets, urine, and human blood serum and high recoveries in the range of 97.9-101.9% were obtained.
