A near-infrared and two-photon ratiometric fluorescent probe with a large Stokes shift for sulfur dioxide derivatives detection and its applications in vitro and in vivo.

Graphical abstract A new near-infrared and two-photon fluorescentt probe with a large Stokes shift was engineered to detect SO 2 derivatives in living cells and mice. Highlights • We have developed a novel near-infrared and two-photon ratiometric probe NIR-SO 2 -TP for sensing SO 2. • The new probe NIR-SO 2 -TP exhibited fast response to SO 2 in less than 12 s. • The unique probe NIR-SO 2 -TP exhibited giant stokes shift (185 nm). • The probe NIR-SO 2 -TP showed excellent sensitivity and high selectivity toward SO 2. • The new probe NIR-SO 2 -TP has been successfully applied to sense SO 2 in living cells, tissues, zebrafish and living mice. Abstract As a critical gaseous signaling molecule, SO 2 is involved in multiple physiological and pathological processes. However, the pathogenesis of many serious diseases including lung cancer, cardiovascular diseases and neurological disorders caused by excessive inhalation of SO 2 is still unknown. Hence, the development of reliable analytical methods for efficiently and specifically monitoring SO 2 in living systems is of significance. In this work, a novel near-infrared and two-photon ratiometric fluorescent probe NIR-SO 2 -TP was first proposed for optical SO 2 sensing. The newly synthesized fluorescent probe NIR-SO 2 -TP , which is based on coumarin-benzopyrylium π-conjugated platform, exhibited high selectivity, rapid response time, lower detection limit and a large Stokes shift (185 nm). Importantly, the novel probe has been successfully applied to sense SO 2 in living cells, tissues, zebrafish and living mice at both near-infrared and two-photon modes. [ABSTRACT FROM AUTHOR]