Tetrahydro[5]helicene-based fluorescent probe for rapid and sensitive detection of bisulfite in living cells

摘要

A new fluorescent probe tetrahydro[5]helicene-malononitrile derivative was designed and synthesized for selective detection of bisulfite. This fluorescent probe exhibites high response speed and selectivity toward HSO3−in PBS solution over other coexisting species accompanied by a distinct fluorescence color change from yellow to blue, which can be visually identified. The probe shows excellent sensitivity to HSO3−and the detection limit is as low as 0.27 μM. Once reacted with HSO3−, the signal-to-background ratio of fluorescence intensity can reach a 45-folds enhancement and the quantum yield dramatically increases from 1.9% to 52.3%. The response mechanism proved to be a nucleophilic addition reaction of probe with HSO3−, which was confirmed by1H NMR, Mass titration and theory calculation. Additionally, the preliminary cell imaging experiments demonstrated that the probe could be used for intracellular bisulfite detection.