▎ 摘　　要

The electrochemical exfoliation method adopted in this study presents the quality variations of the graphene oxide (GO) produced under applied currents flow (Alternating current (AC) and Direct current (DC)). The obtained GOs were reduced by a fast, efficient, and environmentally-friendly electrochemical method using CV without the addition of chemical agents. Subsequently, the r-GOs obtained were used as carbon paste electrode (CPE) modifiers (r-GOAC-CPE and r-GODC-CPE) for the determination of Ciprofloxacin (Cipro) traces in fish tissues, urine and drug samples. The prepared electrodes were characterized by X-ray diffraction (XRD) and thermogravimetric and differential thermal analysis (DTA-TGA). Comparison of the electrochemical performances of each preparation (r-GOAC-CPE and r-GOAC-CPE) has been performed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal experimental parameters, the electro-oxidation peak signal was linearly related to Cipro concentration in the range from 1.0 x 10-7 to 5.0 x 10-5 mol/L for r-GOAC-CPE and from 3.0 x 10- 7 to 5.0 x 10-5 mol/L for r-GODC-CPE. The developed sensors enabled to achieve a detection limit (DL) of 4.08 x 10-9 mol/L and a quantification limit (QL) of 13.36 x 10-9 mol/L for r-GOACCPE and 17.74 x 10-9 mol/L and 59.13 x 10-9 mol/L for r-GODC-CPE. The prepared sensors were successfully applied for Cipro recognition in fish tissues, urine and drug samples.