Parallel G-Quadruplex DNA Structures from Nuclear and Mitochondrial Genomes Trigger Emission Enhancement in a Nonfluorescent Nano-aggregated Fluorine-Boron-Based Dye.

Molecular self-assembly is a powerful tool for the development of functional nanostructures with adaptive optical properties. However, in aqueous solution, the hydrophobic effects in the monomeric units often afford supramolecular architectures with typical side-by-side π-stacking arrangement with compromised emissive properties. Here, we report on the role of parallel DNA guanine quadruplexes (G4s) as supramolecular disaggregating-capture systems capable of coordinating a zwitterionic fluorine-boron-based dye and promoting activation of its fluorescence signal. The dye's high binding affinity for parallel G4s compared to nonparallel topologies leads to a selective disassembly of the dye's supramolecular state upon contact with parallel G4s. This results in a strong and selective disaggregation-induced emission that signals the presence of parallel G4s observable by the naked eye and inside cells. The molecular recognition strategy reported here will be useful for a multitude of affinity-based applications with potential in sensing and imaging systems.