▎ 摘　　要

Polypyrrole-graphene (Ppy-G) composites were prepared by electrochemically polymerizing Au electrodes, which served as the working electrodes for postoperative pain reliever parecoxib sensing. The Ppy-G composite electrodes were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Various concentrations of parecoxib (0.01-10 ppm) were prepared in a drip bag solution of 0.9% NaCl. Prepared Ppy-G was used to evaluate the working electrodes, and the sample solution was measured at frequencies of 100 MHz. The Ppy-1% G electrode exhibited a stronger linearity (R-2 = 0.992) than did the Ppy electrode (R2 = 0.878) when the frequency was fixed at 100 kHz. The proposed system yielded response and recovery times within 1 sec when detecting 0.01 ppm (10 mu g/L) of the postoperative pain reliever parecoxib; thus, the proposed online method is promising for measuring the concentrations of parecoxib in hospital drip bags. Molecular simulations and equivalent circuits were applied to explain the dynamic behaviors of the parecoxib detection on Ppy and Ppy-G systems.