A ratiometric fluorescent on-off Zn2+ chemosensor based on a tripropargylamine pyrene azide click adduct.

A new, easy-to-prepare and highly selective pyrene-linked tris-triazole amine fluorescent chemosensor has been designed from tripropargylamine and pyrene azide using Cu(I)-catalyzed click chemistry. The fluorescence on-off sensor 1 is highly selective for Zn(2+) displaying a ratiometric change in emission. The relative intensity ratio of monomer to excimer fluorescence (M(376)/E(465)) of the sensor increases 80-fold upon the addition of 10 equiv of Zn(2+) ions (with a detection limit of 0.2 μM).