Journal of hazardous materials | 2019
Fibrous strips decorated with cleavable aggregation-induced emission probes for visual detection of Hg2.
Abstract
The widespread contamination and high poisonousness have created significant concerns and thus demands for facile, rapid and selective monitoring of trace Hg2+. Inspired from the unique aggregation-induced emission (AIE) feature, in the current study, novel tetraphenylethylene (TPE) derivatives are prepared containing sulfonic groups for water solubility modulation and carboxyl dithioacetals for Hg2+ sensing. The TPE derivatives are grafted on electrospun fiber as test papers to initiate the AIE activities, while the Hg2+-specific cleavage of dithioacetal groups leads to the release of TPE derivatives and fluorescence turn-off. The decrease in the fluorescence intensities of fibrous mats could be fitted with Hg2+ levels for quantitative analysis, and the fibrous mats turn from green to bluish-green and then to blue in the presence of different Hg2+ levels. The limit of detection (LOD) reaches as low as 20\u202fnM Hg2+, satisfying the threshold detection in drinking water, and the Hg2+ sensing indicates negligible interference from other metal ions and pH variations. The detected Hg2+ levels in lake water are consistent with the added amount with a recovery rate of over 98 %. It demonstrates a feasible strategy to integrate Hg2+-cleavable AIE probes on fibrous strips for real-time, highly specific and naked-eye detection of trace Hg2+.