First fluorescence sensor for detecting pesticide starane

Although the fluorescence sensor for ions and organic functional molecules had been studied extensively, only a few fluorescent probes were reported for sensing pesticides. In this research, the first example of fluorescent sensor for pesticide starane was reported based on thiourea-bridged bis-tetraphenylimidazole (TBTPI). TBTPI was synthesized by bridging two tetraphenylimidazole units with thiourea spacer in yield of 81 %. It displayed the obvious "turn-on" blue-green fluorescence after detecting starane with high sensing selectivity and sensitivity in aqueous media. The detecting limitation was 4.2 × 10−6 M. The sensing mechanism was elucidated by 1H NMR, MS and fluorescence Job's plot. The sensing ability of TBTPI for starane was successfully applied for starane paper test, starane water samples and Loquat leaves with starane spraying, suggesting the excellent application potential for TBTPI on detection of starane in agriculture and daily life.