Fluorescence and Naked-Eye Detection of Pb²⁺in Drinking Water Using a Low-Cost Ionophore Based Sensing Scheme

Abstract

Drinking water contamination of lead from various environmental sources, leaching consumer products and intrinsic water-pipe infrastructure is still today a matter of great concern. Therefore, new highly sensitive and convenient Pb2+ measurement schemes are necessary, especially for in-situ measurements at a low-cost. Within this work dye/ionophore/Pb2+ co-extraction and effective water phase de-colorization was utilized for highly sensitive lead measurements and sub-ppb naked-eye detection. Low-cost ionophore Benzo-18-Crown-6-ether was used, and a simple test-tube mix, shake and separate procedure was developed. Instrumental detection limits were in the low ppt region (LOD=3, LOQ=10), and naked-eye detection was 500 ppt. Note, however, that this sensing scheme still has improvement potential as concentrations of fluorophore and ionophore were not optimized. Artificial tap-water samples, leached by a standardized method, demonstrated drinking water application. Implications for this method are convenient in-situ lead ion measurements.