New Generation of Electrochemical Sensor for Sub-Nanomolar Zn (II) Ion Detection Based on Nano- Sized Ion Imprinted Polymer and Functionalized Multi-Walled Carbon Nanaotube Composite Modified Glassy Carbon Electrode

Abstract

A new selective and sensitive electrochemical sensor was prepared by film coating of Zinc (II) ion imprinted polymer (IIP) nanoparticle and functionalized multi-walled carbon nanotube (MWCN) composite on glassy carbon electrode (GCE). The prepared electrochemical sensor was applied for the sensitive determination of Zinc (II) ion by square wave anodic stripping voltammetry (SWASV) method. The GCE/IIP-MWCNT modified electrode showed improved electrochemical behavior as compared to bare GC electrode. An optimum procedure was used for the fixation of Zn(II)-8-hydroxyquinoline to styrene-ethylene dimethacrylate copolymer and the resultant IIP nanoparticles characterized by Fourier Transform Infrared ( FTIR), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). The effects of different experimental variables such as pH, deposition time, and deposition potential were optimized for electrochemical determinations. The resultant IIP showed a selective sorbent for Zinc (II) ion. Functionalized MWCNT was applied in construction of as prepared modified electrode, exhibits large surface area, enhanced electron transfer kinetics, and improved Zn (II) ion diffusion. Under the optimal conditions, the resulting calibration curve exhibited a linear response within a concentration range of 5×10-12 to 15×10-8 mol/L-1 with excellent detection limit 5×10-12mol/L-1. Finally, the method was successfully applied for the determination of zinc (II) ion in the real water samples, and the obtained results were verified by inductively coupled plasma (ICP).