Construction of multi-channel fluorescence sensor array and its application for accurate identification and sensitive quantification of multiple metal ions

Abstract

Herein, a small molecule based multi-channel fluorescent sensor array (SA) for accurate discrimination and sensitive quantitation of multiple heavy metal ions was developed, with its detection mechanism simulates an electronic tongue. The synergistic effects of the differentiated affinity of chelator for metal ions and multiple emission channels of sensors led to the diverse emission intensity change and wavelength switch, displaying obvious cross-reactivity and diversified signal output. Treated with linear discriminant analysis (LDA), this diversified multi-channel output allowed correct and high-resolution discrimination of 11 heavy metal ions at different concentration as well as multivariate mixture of hard-distinguish metal ions. Further titration experiment exhibited the regular arrangement of each metal ions in different extension directions at the range of 0–20 μM in 3D LDA plot, endowing SA array with the ability to identify and quantify each heavy metal ion. The feasibility of the SA array was also verified by the accurate detection of a large number of actual water samples. This strategy enables simple, efficient, sensitive identification and quantification of multiple metal ions in real water, demonstrating its potential for simplification of water quality analysis process.