A turn-on fluorescent chemosensor based on aggregation-induced emission for cyanide detection and its bioimaging applications

Abstract

Numerous efforts are contributed to develop fluorescent sensors for qualitative and quantitative detection of cyanide anion (CN−) as it is inevitably utilized in various fields and detrimental to human health and ecosystem. Herein, a new fluorescent probe TCNT with the feature of aggregation-induced emission was designed and synthesized. Owning a large Stokes shift (˜148 nm) and red fluorescent emission (596 nm), TCNT showed high specific and sensitivity (detection limit equals to 0.35 μmol L−1) to CN− with a 2.53-fold enhancement of quantum yield in aqueous solution. The recognition mechanism of TCNT sensing cyanide was ascribed to nucleophilic attack of CN− toward vinyl group, which was confirmed by 1H NMR titration and DFT calculations. Test strips loaded with TCNT demonstrated its convenient detection for cyanide ion in real environment. In addition, because of good biocompatibility and low cytotoxicity, TCNT was applied for monitoring the levels of CN− in HeG-2 cells by confocal laser scanning microscopy. Moreover, fluorescence imaging of isolated organs of mice proved that TCNT is capable of achieving bioimaging in live organisms.