A dansyl-based fluorescent probe for selectively detecting Cu2+ and imaging in living cells

Copper is a crucial transition metal ion that plays an essential role in environmental, biological, and chemical systems. Therefore an efficient method for detection of copper ions is significant. In this work, a sulfonamide-based probe containing a dansyl fluorophore was synthesized in good yield. This probe exhibited good selectivity and sensitivity for copper ions in aqueous solution without any interference from other metal ions. And it displayed a very low detection limit (2.91 x 10(-8) M) for Cu2+, which supported its further application in bioimaging. Its good water-solubility, bio-compatibility and cell permeability leads it to be employed as an efficient biomarker to monitor the level of Cu2+ in living cells. The binding model between fluorescent probe and Cu2+ was evaluated by density functional theory calculations.