posted on 2021-07-06, 16:36authored byMing Jin, Jing Li, Yang Chen, Jie Zhao, Jiahui Zhang, Zhen Zhang, Peiyao Du, Libing Zhang, Xiaoquan Lu
In
the past 10 years, many fluorescent probes have been developed
to recognize G-quadruplexes (G4s) since G4s play an important role
in biological systems. However, the selectivity and sensitivity of
existing probes for G4s limit their further applications. Herein,
we design and synthesize a new probe (TOVJ) by introducing 9-vinyljulolidine
into TO. The new probe exhibits almost no fluorescence in an aqueous
solution. Upon interacting with G4s, especially the antiparallel G4s,
the fluorescence intensity was greatly enhanced (maximum 2742-fold)
with a large Stokes shift of 198 nm and the maximum emission peak
at 694 nm (near-infrared region). TOVJ showed high sensitivity and
selectivity to G4s over other DNA topologies (ssDNA/dsDNA), especially
to antiparallel G4s. For antiparallel human telomere G4 detection,
the limits of detection of Hum24 and 22AG Na+ were as low
as 164 and 231 pM, respectively. This indicates that TOVJ is a highly
sensitive fluorescence sensor that can be effectively used for antiparallel
human telomere G4 detection. The result of live-cell imaging showed
that TOVJ could enter live cells and locate in the mitochondria.