▎ 摘　　要

An ultrasensitive electrochemical sensor for the selective voltammetric measurement of trace ceftizoxime (CFX) was described. Modification of a pencil graphite electrode (PGE) was first done with the reduced graphene oxide (r-GO) and, afterward, Preyssler nanocapsules (PNCs) were generated onto the r-GO/PGE. The surface morphology of the synthetic compounds has been evaluated using FT-IR, FE-SEM, TEM, and SEM techniques. Adsorptive differential pulse voltammetry (AdDPV), cyclic voltammetry (CV), chronocoulometry (CC) and electrochemical impedance spectroscopy (EIS) were employed to investigate the CFX electrochemical characteristic on the modified electrode (PNCs/r-GO/PGE). The electron transfer coefficient (?) between PNCs/r-GO and PGE was calculated using the obtained CV. Also, chronocoulometry experiments were performed in the absence and presence of CFX to calculate diffusion coefficient (D) and capacity of adsorption (?S) of CFX for PNCs/r-GO/PGE thin film. Under the optimized conditions, the calibration curve of the CFX has a linear concentration range from 1.0 ? 10-11 to 3.0 ? 10-8 M (R2 = 0.9993) and a detection limit of 1.8 pM. The developed electrochemical sensor shows greater sensitivity than the earlier reported techniques for the CFX measurement. The sensor was successfully utilized to determine the trace amounts of CFX in pharmaceutical and blood serum with suitable recoveries.