A highly selective colorimetric sensor for ferrous ion based on polymethylacrylic acid-templated silver nanoclusters

A highly selective colorimetric sensor for detecting Fe2+ was proposed using the water-soluble silver nanoclusters (AgNCs) for the first time. AgNCs were synthesized via a one-pot reaction by using polymethacrylic acid (PMAA) as both a template and a reducing agent. The as-prepared AgNCs showed highly selective and sensitive detection toward Fe2+ over Fe3+ and other cations. Upon addition of Fe2+, the absorbance at 447 nm increased as a linear function of the increasing concentration of Fe2+. Parameters possibly affected the sensor sensitivity were investigated and optimized. The proposed sensor could efficiently be used for Fe2+ sensing at very low concentration with the limit of detection of 76 nM and the linear working concentration range of 5-100 mu M. The feasibility of the proposed sensor for determining Fe2+ in the iron supplement tablet samples was also studied and compared with 1,10-phenanthroline method as well as inductively couple plasma-optical emission spectroscopy (ICP-OES). The Fe2+ content obtained from three methods were not significantly different signifying the high accuracy of the proposed sensor. (C) 2014 Elsevier B.V. All rights reserved.