ESIPT-based highly selective fluorescent probe for organic azides through Staudinger ligation

Based on Staudinger ligation, a novel ESIPT-based fluorescent probe 2-[2′-(ortho-diphenylphosphinophenyl) carboxyphenyl]benzothiazole (CBT) was developed for detection of organic azides with the detection limit of 227 nM. The probe has shown selective and sensitive response to organic azides over other non-azido analytes. The probe was used as a fluorescence turn-on chemosensor for phenyl azide in living hepatoma SMMC-7721 cells, indicating its potential application for detection of organic azide derivatives in biological systems. Moreover, the probe provides a very convenient method to qualitatively monitor the formation of organic azides by TLC staining experiments.