▎ 摘　　要

A novel, simple, sensitive and selective sensor based on carbon paste electrode (CPE) modified by Sodium Montmorillonite nanoclay (NaMM)/Electroreduced Graphene Oxide (ERGO) Composite was developed for the electrochemical determination of Cefotaxime (CEF). The electrooxidation of CEF was studied on modified carbon paste electrode using cyclic voltammetry and differential pulse voltammetry as diagnostic techniques. It was found that the oxidation peak current of CEF on the modified carbon paste electrode was greatly improved compared to that obtained on the unmodified carbon paste electrode. The electronic transfer property of the NaMM/ERGO/CPE was characterized by electrochemical impedance spectroscopy (EIS). Also, morphology of NaMM and ERGO were characterized by scanning electron microscopy (SEM). Under optimized conditions, the modified electrode exhibited a linear response over two linear concentration ranges from 0.5 to 40 nM and 40 to 2400 nM CEF, with a detection limit of 0.1 nM. The proposed sensor was successfully applied for monitoring of CEF in serum and urine samples and satisfactory results were obtained.