Metal ion-prompted pyrene–excimer formation via an anion-mediated process and its application for a ratiometric Zn2+ chemosensor with high selectivity over Cd2+

The combination of [(2,2′-dipicolylamino)butyl]pyrene (1) and pyrophosphate (PPi) was shown to be functional as a ratiometric Zn2+ ion fluorescent probe. This was changed to Zn2+-1 upon the addition of Zn2+, which was dimerized by a PPi-mediated self-assembly, leading to a relatively strong emission fluorescence with a large bathchromic shift. This chemosensor can detect Zn2+ in an aqueous solution of physiological pH with high selectivity toward Zn2+ over a variety of metal ions, including Cd2+, and has a low detection limit of 0.64 μM in an aqueous buffer system.