A benzo(f)quinolinium fused chromophore-based fluorescent probe for selective detection of c-myc G-Quadruplex DNA with a red emission and a large Stocks shift

Abstract Accumulating evidence in recent years has suggested that G-Quadruplex DNAs may play important roles in gene expression and genomic stability in vivo. Specially, c-myc G-Quadruplex that exists in the promoter of oncogene is an attractive target in the pathway of cell proliferation and senescence. The development of small-molecule fluorescent probes for c-myc G-Quadruplex DNA has attracted significant attention. This work presented a benzo(f)quinolinium fused chromophore-based fluorescent probe L-1 for the detection of c-myc G-Quadruplex DNA using N-(2-hydroxyethyl)piperazine moiety as a binding unit. This probe exhibiting a red emission and a large Stocks shift was found to be selective and sensitive for “light-up” detection of c-myc quadruplex DNA over duplex DNA and other G-quadruplexes. It stabilized c-myc G-Quadruplex DNA and effective inhibited in vitro DNA synthesis. Binding studies indicated that the fluorescent response of L-1 mainly arised from end-stacking binding mode. Furthermore, L-1 was applicable to visualize the cellular nucleus in living cells.