Research Progress in Cyanine-Based Recognition Probes for G-Quadruplex DNA

Guanine-rich (G) DNA sequences can form a special nucleic acid secondary structure called G-quadruplex DNA, which is widely distributed in eukaryotic genomes and is closely associated with the formation and development of cancer.The development of small molecule fluorescent probes targeting G-quadruplexes is of great significance for the study of the biological functions of G-quadruplexes in organisms and for targeting anti-cancer drugs.The cyanine dyes are widely used as fluorescent dyes for biolabelling, with the advantages of multiple modification sites and adjustable spectral range.The rigid structural part of the backbone can be bound to the end of the G-quadruplex or groove through π-π stacking, hydrophobic interaction and other non-covalent bonding, inducing different spectral signal changes of cyanine dyes to achieve selective recognition of the G-quadruplex.This has become a hot topic of research in the field of G-quadruplex recognition in recent years.Herein, the research progresses in the field of G-quadruplex recognition probes based on cyanine dye are reviewed.Molecular design and propertis of this kind of probes are briefly introduced, and the affinity and selectivity of probes for G-quadruplex DNA are also commented.Moreover, the future trends of cyanine-based recognition probes for G-quadruplex are briefly introduced.