A fluorescent probe based upon anthrancene-dopamine thioether for imaging Hg²⁺ ions in living cells

A novel anthrancene-dopamine thioether L compound was designed as fluorescent probe for detecting Hg²⁺ in living cells sample. L exhibits a good sensitive and selective recognition towards Hg²⁺ ions in the presence of other important relevant metal ions and amino acids in HEPES solution. The addition of Hg²⁺ causes a marked enhancement in the fluorescence emission intensity with the detection limit as low as 1.1×10^-6M, combining with obvious colormetric change from colorless to pale brown. Mechanistic studies show that catechol group and sulfur atom in L all participate in the coordination with Hg²⁺, though catechol group contributes mainly to chelation-enhanced fluorescence enhancement and sulfur atom to selectivity. Furthermore, L demonstrates good cell permeability and compatibility for sensitive fluorescent detection of Hg²⁺ in HepG2 cells. This present probe will have broad applications in biological imaging.