BODIPY- imine based fluorescence "turn on" chemosensor for selective sensing of Hg<SUP>2+</SUP>

The detection of mercury has gained considerable attention due to its both environmental and biological impacts. In this study, a BODIPY- imine chemosensor (3) having an imine molecule at the meso position of the BODIPY core was synthesized, and its structure was characterized by spectroscopic and analytical methods as well as single crystal XRD. Chemosensor 3 showed a poor emission band in the DMSO/H2O (9:1 v/v) solvent system (Phi(Fl) < 0.01). Upon the addition of Hg2+, the fluorescence intensity of 3 increased notably with a 0.031 Phi(Fl) value, and the limit of detection for Hg2+ was calculated as 0.90 mu M. The sensing mechanism of 3 was investigated H-1 NMR titration studies and Hg2+ ion induced hydrolysis of the imine double bond and thus activating the PET OFF proccess. The BODIPY- imine compound (3) can be used as reaction-based fluorescence probe for the sensing of Hg2+ ion.