Synthesis of NIR fluorescent thienyl-containing aza-BODIPY and its application for detection of Hg2+: Electron transfer by bonding with Hg2+

Utilizing 2-vinylthiophene as the starting material, the thienyl-containing aza-BODIPY 1 was successfully prepared. Aza-BODIPY 1 absorbs at 760 nm and emits at 782 nm in CHCl3 in NIR region. Aza-BODIPY 1 as a NIR turn-off chemosensor was highly selective to Hg2+. The fluorescence quenching is due to that the electrons from the thienyl groups to the aza-BODIPY core were transferred after binding with Hg2+. The chemosensor 1 can be used to detect Hg2+ in MCF-7 cells, indicating its potential application for studying the effect of Hg2+ in biological system.