Application of a Polypyrrole/Carboxy Methyl Cellulose Ion Imprinted Polymer in the Electrochemical Detection of Mercury in Water

Sulphur containing carboxy methyl ion imprinted polymers (S-IIPs) were applied as an electrode modifier for the electrochemical detection of Hg(II). A bare glassy carbon electrode (GCE) was modified by electro-polymerizing a layer of pyrrole and then drop coating with S-IIPs. The bare GCE, GCE/polypyrrole (GCE/PPy), GCE/polyprrole/non-ion imprinted polymers (GCE/PPy/NIPs) and the GCE/polypyrrole/sulphur ion imprinted polymers (GCE/PPy/S-IIPs) electrodes were characterised with Fourier Transmission Infrared (FTIR) and electrochemical impendence spectroscopy (EIS). The square wave anodic stripping voltammetry (SWASV) optimised conditions for the GCE/PPy/S-IIPs were: a pH of 3, deposition potential of −1.0 V, pre-concentration time of 60 s and 0.1 M HCl supporting electrolyte. The developed ion imprinted polymer electrochemical sensor was applied in the detection of Hg(II) in water. A detection limit of 0.1 μg L⁻¹ was calculated within a concentration range of 20–800 μg L⁻¹. The sensor was selective in the presence of interfering ions and method was validated with inductively coupled plasma-optical emission spectrometry (ICP-OES) using real water and standard water samples.