An ESIPT-induced NIR fluorescent probe to visualize mitochondrial sulfur dioxide during oxidative stress in vivo

Abstract

Based on the change in electron distribution of the benzopyrylium unit before and after sulfite addition, a 2-(2′-hydroxyphenyl)benzothiazole (HBT)-based fluorophore generated the excited state intramolecular proton transfer (ESIPT) process with a near-infrared enhanced emission at 836 nm and a large Stokes shift (286 nm). The probe was applied to image SO₂ derivatives in cells and mice. Our data will provide new ideas for the development of ESIPT-based fluorescence probe with longer wavelength emission.