A novel red-emitting fluorescent probe for the highly selective detection of Hg2+ ion with AIE mechanism

A novel red-emitting fluorescent probe TBTS for the highly selective detection of mercury (Hg2+) ion has been developed, which was constructed with triphenylamine-benzothiadiazole skeleton. Probe TBTS was barely emissive in HEPES buffer solution (pH = 7.4, 10 mM, with 3% DMSO). As the presence of Hg2+ ion, the dithioacetal unit in probe TBTS was hydrolyzed to be aldehyde group, consequently resulting in the intense red emission via aggregation-induced emission (AIE) mechanism. This sensing behaviour was completed within 2.5 min, and the detection limit toward Hg2+ ion was calculated to be 90 nM. More importantly, probe TBTS exhibited the excellent biocompatibility, and it was capable of monitoring Hg2+ ion in living cells.