▎ 摘　　要

The electrochemical behavior of furosemide was investigated at the magnetic graphene oxide functionalized by chlorosulfonic acid-modified glassy carbon electrode (Fe3O4-GO-SO3H-GCE) in phosphate buffer solution (PBS), pH 6.8. Cyclic voltammetric study indicated that the oxidation process is irreversible and diffusion controlled. The number of exchanged electrons in the electro-oxidation process was obtained, and the data indicated that furosemide is oxidized via two one-electron steps. The results revealed that Fe3O4-GO-SO3H promotes the rate of oxidation by increasing the peak current. The diffusion coefficient and electron-transfer coefficient of furosemide were found to be 2.18 x 10(-6) cm(2) s(-1) and 0.46, respectively. A sensitive, simple and time-saving differential-pulse voltammetric procedure was developed for the analysis of furosemide. The results show that by using the proposed method, furosemide can be determined with a detection limit of 0.11 mu M. Finally, the applicability of the method to direct assays of spiked human serum and urine fluids is described.