An isaindigotone-based NIR fluorogenic probe for visualizing mitochondrial DNA G-quadruplexes in living cells

Growing evidence suggests that mitochondrial DNA G-quadruplexes (mtDNA G4s) play a critical role in modulating mitochondrial function. In this study, a novel fluorescent probe, IS-HX, was designed based on a fluorinated isaindigotone scaffold linked to dihydroxanthene units, enabling specific imaging of mtDNA G4s. This probe exhibits not only near-infrared (NIR) absorption and emission but also high selectivity and specificity for imaging mtDNA G4s in living cells. Using IS-HX, we successfully monitored the dynamic changes of mtDNA G4s under glycolysis-induced conditions. This probe may serve as an effective tool for the visualization of mtDNA G4s in living cells.