A novel colorimetric fluorescent probe for sensing bisulfite detection in plant and zebrafish.

Sulfur dioxide (SO₂) and its derivatives (SO₃^2- and HSO₃^-), are important active sulfur species that play significant roles in physiological processes. Fluorescence probe imaging technology, due to its high temporal and spatial resolution, real-time non-invasive and non-destructive detection, has emerged as a valuable tool for studying SO₂ in biological systems. In this study, we presented a colorimetric fluorescent probe for the detection of HSO₃^-. The structure of probe TPN-BP consists of a triphenylamine group and a benzopyrylium group that are connected by a vinyl double bond. The benzopyrylium group in probe TPN-BP, which carries a positive charge, serves two important functions: enhancing water solubility, allowing for its effective use in fully aqueous environments, and acting as a fluorescence quencher for the triphenylamine group. Upon interaction with HSO₃^-, probe TPN-BP exhibited significantly increase in fluorescence at 480 nm, causing the solution to change from blue to colorless. Spectral experiments showed that probe TPN-BP showed quick response time (10 s), high sensitivity (12.7 nM), and excellent selectivity towards HSO₃^-. It is worth noting that probe TPN-BP has been successfully used for fluorescence imaging and detection of HSO₃^- in plants and zebrafish. The results of this study indicated that probe TPN-BP can be used as a promising tool for the research and monitoring of SO₂ in living organisms.