A quinoline-coumarin near-infrared ratiometric fluorescent probe for detection of sulfur dioxide derivatives

Abstract

Sulfur dioxide derivatives (HSO₃^- and SO₃^2-) play an important role in food preservative, antibacterial, antioxidant and other aspects, so it is urgent for us to develop more efficient detection methods to broaden their application in biochemical research and related disease diagnosis. Fluorescent probes are of particular interest because of their simplicity and high temporal and spatial resolution. Herein, we constructed a new near-infrared (NIR) fluorescence probe, CQC, composed of coumarin fluorophore and quinoline fluorophore, for detecting SO₂ derivatives. The near-infrared emission probe CQC with a large Stokes shift (260 nm) not only kept the distance between the two emission peaks large enough (165 nm), but also had a particularly high energy transfer efficiency (99.5%), and was particularly sensitive to the detection of HSO₃^-/SO₃^2- (LOD: 0.1 μM). The powerful probe CQC succeeded in real-time visualizing endogenous HSO₃^-/SO₃^2- in living cells.

Keywords: Cell image; FRET; NIR; Ratiometric fluorescent probe; SO(2) derivatives.