A new probe for fluorescent recognition of Hg2+ in living cells and colorimetric detection of Cu2+ in aqueous solution

We developed a new probe based on rhodamine B and 5-ferrocenyl-1,3,4-thiadiazole. The probe can be used to sensitive and selective fluorescent recognition of Hg2+ with good quantum yield. The fluorescence intensity was remarkably increased upon the addition of Hg2+ within 1 or 2 min with about 27 fold enhancement. Additionally, the turn-on fluorescent probe with good membrane-permeable property was successfully applied to microscopic imaging for the detection of Hg2+ in HeLa cells. The probe facilitates also naked-eye detection of Cu2+ in aqueous solution.