Pillar[5]arenes modified tetraphenylethylene as fluorescent chemosensor for paraquat detection

Pesticide pollution has become a severe challenge for harming food quality and human safety. Therefore, it’s urgent to develop sensitive methods to detect and analyse pesticides. Herein, we successfully developed a new turn-on fluorescent chemosensor (TPE-4P), a tetraphenyl ethylene derivative modified with four pillar[5]arenes, which could sensitively, selectively, and rapidly detect the pesticide paraquat. In our study, we took full advantage of both the host-guest strategy and aggregation-induced emission (AIE) to achieve fluorescent enhancement of the chemosensor for paraquat, in which four pillar[5]arenes as the recognition units can selectively capture paraquat. The formation of the supramolecular complexes based on the interlaced host-guest interactions effectively restricted the intramolecular single-bond rotation and skeletal vibration, resulting in the intensive fluorescent emission. The detection limit for paraquat was low enough to reach 154.1 nM, and the detection time was short enough to meet the rapid detection conditions. Moreover, the test strips loaded-TPE-4P facilitated the detection process and achieved the semi-quantitative analysis for paraquat in real spiked samples. In addition, TPE-4P could respond to paraquat in living zebrafish obviously. These results suggest that the cooperation of host-guest and AIE chemistry could become useful for the design to detect some appropriate organic molecules.