Near-Infrared Fluorescent Switch-On Probe for Guanine-Quadruplex Imaging with Extremely Large Stokes Shift

To visualize the guanine-quadruplex (G4) nucleic acids in cells or in biological tissues, near-infrared (NIR) fluorescent probes that can respond specifically to G4 nucleic acids are required. Herein, an NIR fluorescence switch-on probe for G4 imaging having higher selectivity and extremely large Stokes shift (ca. 220 nm) was successfully developed by the modification of our original tripodal quinone-cyanine fluorescent dye. The target binding-induced intramolecular stacking interaction of the probe might cause red shifting of the fluorescence emission. The NIR fluorescence switch-on probe developed here might contribute largely to revealing the behaviors of G4 nucleic acids not only in cells but also in biological tissues.

Automated summary

In this study, an NIR fluorescence switch-on probe for G4 imaging with higher selectivity and large Stokes shift was developed. This probe may contribute significantly to understanding the behaviors of G4 nucleic acids in cells and biological tissues.