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

[Display omitted] •Developed a multi-channel fluorescence sensor array consisting of four multi-emission and multi-response fluorescent sensors.•Eleven metal ions, as well as multivariate mixture of several difficult-to-distinguish metal ions, were accurately discriminated.•The array system enables ultra-sensitive detection of multiple heavy metal ions.•A “safe area” is constructed to quickly distinguish clean water and contaminated water. 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.