Zinc ion detection using a benzothiazole-based highly selective fluorescence "turn-on" chemosensor and its real-time application.

A new photochromic fluorescence chemosensor was devised and effectively synthesized using benzothiazole and imidazopyridine derivatives. A "turn-on" fluorescence sensor BIPP for Zn 2+ detection was developed and has a quick response, excellent sensitivity, and remarkable selectivity over other metal ions. When Zn 2+ was added to the BIPP solution, a new strong fluorescence emission peak at 542 nm formed with a considerable increase in intensity. The fluorescence color of the BIPP solution changed from blue to bright green. The binding ratio 8 : 2 was found between BIPP and Zn 2+ by the results of Job's plot, HRMS and 1 H-NMR. The detection limit (LOD) of BIPP towards Zn 2+ was determined to be 2.36 × 10 -8 , which is remarkably low. The ability to detect Zn 2+ in real water samples demonstrates that BIPP may also be used in environmental systems. Additionally, BIPP can be used to measure Zn 2+ levels in living cells.