Selective and simultaneous detection of Zn2+, Cd2+, Pb 2+, Cu2+, Hg2+ and Sr2+ using surfactant modified electrochemical sensors

The 1-(3-chlorophenyl)-3-dodecanoylthiourea (Cl-DPTU) surfactant modified GCE (Cl-DPTU/GCE) was developed for the selective and sensitive simultaneous detection of six metal ions. The as developed electrochemical sensing platform was characterized using electrochemical impedance spectroscopy (EIS) and chronocoulometry to determine the charge transfer characteristics. The charge transfer behavior of bare GCE and Cl-DPTU/GCE was compared and the results revealed the modifier to significantly improve the charge transduction between the redox probe and transducer. The square wave anodic stripping voltammetry (SWASV) was then performed to investigate the electrochemical catalytic activity of the modifier. The sensing limits of Cl-DPTU/GCE under optimized experimental conditions for Cd2+, Cu2+, Hg (2+), Pb2+, Zn2+, and Sr2+ ions were obtained as 6.45 nM, 7.85 nM, 9.15 nM, 11.0 nM, 16.9 nM, and 178.8 nM respectively. The selectivity of Cl-DPTU/GCE was examined from the influence of interfering agents on the signals of the targeted metal ions. Likewise, the applicability of the SWASV was checked in real water samples. Interestingly the recovery percentages of nearly 100% for all water samples evidenced authenticity of Cl-DPTU/GCE for multiple metal ions determination in real water samples. Moreover, computational studies were performed and the computed parameters supported the experimental results. (C) 2019 Elsevier Ltd. All rights reserved.