A mitochondria-targetable fluorescent probe for ratiometric detection of SO2 derivatives and its application in live cell imaging

Abstract

A fluorescent probe (DBT) based on conjugation of 2,3-dimethylbenzo[d]thiazol-3-ium iodide to 3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylbenzaldehyde for the detection of sulfur dioxide derivatives (HSO3−/SO32−) has been developed. DBT exhibits highly selective colorimetric and ratiometric fluorescence dual response to HSO3− with a fluorescence detection limit of 3.50×10−7M. The HSO3− sensing mechanism was confirmed to undergo nucleophilic addition of HSO3− to alkene double bond of DBT as evidenced by 1H NMR and HRMS analysis. The probe is MCF-7 cell permeable and applicable for fluorescence imaging of exogenous and intrinsically generated intracellular SO2 derivatives in the living cells. Fluorescence co-localization studies reveal that DBT is a mitochondria-targetable fluorescent probe. Thus, DBT has potential application for exploring the role played by SO2 derivatives in biology.