Development of a new colorimetric and red-emitting fluorescent dual probe for G-quadruplex nucleic acids.

A tailor-made colorimetric and red-emitting fluorescent dual probe for G-quadruplex nucleic acids was developed by incorporating a coumarin-hemicyanine fluorophore into an isaindigotone framework. The significant and distinct changes in both the color and fluorescence of this probe enable the label-free and visual detection of G-quadruplex structures.