Selective voltammetric sensor for nanomolar detection of silver ions using carbon paste electrode modified with novel nanosized Ag(I)-imprinted polymer

In this paper, a novel nanosized silver imprinted polymer was successfully synthesized for the stripping voltammetric detection of silver ions. The Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and thermogravimetric analysis (TGA) were used to characterize the as prepared ion-imprinted polymer (IIP). The electrochemical procedure was based on the accumulation of silver ions at the surface of a modified carbon paste electrode (MCPE) with nanosized silver IIP and multi-walled carbon nanotubes (MWCNTs). After optimization, the resulting electrode exhibited a linear relationship toward Ag(I) concentrations ranging from 0.5 x 10(-9) to 2.8 x 10(-7) M. The limit of detection (LOD) was found to be 1.2 x 10(-10) M (S/N = 3). The relative standard deviation (RSD) for 9 successive measurements at different electrodes was found to be 2.8% (conc.: 50.0 nM). The interference studies showed that the several common metal ions did not interfere with the quantitative silver determination. Finally, because of high selectivity and sensitivity of the proposed modified electrode, it was applied for determination of silver in the environmental water samples and the certified reference material. (C) 2016 Elsevier B.V. All rights reserved.