A near-infrared and two-photon dual-mode fluorescent probe for the colorimetric monitoring of SO2in vitro and in vivo

Abstract

SO₂ has been recently identified as an essential gas messenger followed by NO, CO and H₂S. However, abnormal concentrations of SO₂ in our bodies can cause many diseases. Thus, the real-time monitoring of SO₂ to well define the generation, physiological and pathological functions of SO₂ is urgently needed. In this work, we developed a novel SO₂ fluorescent probe on the basis of the conjugation of semi-cyanine and coumarin derivate dyes with superior features, such as near-infrared (NIR) and two-photon dual-mode monitoring, a large Stokes shift (175 nm), ultrafast response towards SO₂ (within 10 s), high selectivity and photostability. Furthermore, this probe could sense SO₂ by dual colorimetric and fluorescence means. In biological imaging, the probe was able to trace exogenous and endogenous SO₂ in living cells, mitochondria, E. coli, zebrafish and mice under an NIR and two-photon dual-mode. These results demonstrated that the probe has strong potential for studying the physiological and pathological functions of SO₂in vitro and in vivo.