Abstract
In this paper, we present a simple, sensitive and low-cost electrochemical sensor based on an organic layer of EDTA-NQS (1,2-napthaquinone-4 sulphonic acid sodium salt) formed on the surface of a glassy carbon electrode (GC) for the first time. The electrochemical characteristics of the newly fabricated EDTA-NQS/GC sensor were investigated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) techniques. Experimental results confirmed that the new sensor showed superior analytical performance for the simultaneous detection of heavy metals trace in well separated anodic peaks even in the existence of some interfering species. The peak potentials for Cd2+, Pb2+, and Cu2+ are - 0.842, - 0.795 and - 0.285 V (vs. Ag/AgCl), respectively. In addition, it is sensitive to detect some transitional elements like Fe3+ and Hg2+ at - 0.027 and + 0.206 V. The detection limit for Cu2+ and Pb2+ was estimated to be 10.2 and 15.4 nM, respectively. Eventually, the developed sensor was successfully applied to detect contaminants in various cosmetic samples. A mechanism for sensing model has been proposed and discussed. (C) 2021 Elsevier B.V. All rights reserved.