Simultaneous determination of cefotaxime and nimesulide using poly(L-cysteine) and graphene composite modified glassy carbon electrode

Abstract

The present work proposes a voltammetric sensor for the simultaneous determination of cefotaxime (CEF) and nimesulide (NIM) using poly(L-cysteine) and graphene composite modified glassy carbon electrode (GR/p(L-Cys)/GCE). The electrochemical behaviors of CEF and NIM at the GR/p(L-Cys)/GCE were characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Poly(L-cysteine) and graphene produce a synergetic catalytic effect on the electrochemical oxidation of CEF and NIM. Under optimized conditions, the well-defined and separated oxidation peaks of CEF and NIM were observed at 0.72 V and 0.97 V, respectively. The oxidation peak currents of CEF and NIM are linear to the concentrations over the range of 1.0 μM – 60.0 μM and 1.0 μM – 55.0 μM with the detection limits of 0.4 μM and 0.3 μM, respectively. The GR/p(L-Cys)/GCE enabled the simultaneous determination of CEF and NIM in tap water and lake water samples, and the recoveries from 94% to 107% were obtained.