A bifunctional “Turn On” fluorescent probe for trace level Hg2+ and EDTA in aqueous solution via chelator promoted cation induced deaggregation signalling

A squaraine-based bifunctional fluorescent probe with dithiocarbamate (DTC) side arms for Hg2+ and EDTA has been designed and synthesized. The fluorescence response of SQ-1 was investigated with addition of EDTA and Hg2+. SQ-1 exhibits a selective bifunctional “off-on” fluorogenic response to Hg2+ and EDTA in aqueous solution via chelator promoted cation induced deaggregation signalling, with a low detection limit of 1.3 × 10−8 M for Hg2+ and 8.7 × 10−8 M for EDTA.