posted on 2020-07-29, 18:09authored byXianxian Zhao, Liangliang Zhang, Weiying Gao, Xingle Yu, Wei Gu, Weiling Fu, Yang Luo
In situ spatiotemporal microRNA (miRNA) imaging
in mammal cells plays an essential role in illustrating its structures
and biological functions. Herein, we proposed a near-infrared (NIR)
light-activated nanoprobe for high-sensitive in situ controllable miRNA imaging in living cells. The NIR-activated nanoprobe
employed an upconversion nanoparticle that acted as a NIR-to-UV transducer
to trigger the following photocleavage toward a dumbbell DNA probe
tethered on the surface of the nanoparticle. The structure change
of the dumbbell probe then induced a catalytic hairpin assembly of
target miRNAs, by which in situ readout of the amplified
fluorescence signal was enabled. Additionally, both intracellular
miRNA imaging and accurate quantification in live cells were realized
without damaging the cell membranes. Compared with conventional in situ strategies, the proposed approach remarkedly increases
imaging efficiency by eliminating those unfavored intercellular molecular
imaging backgrounds. We assured that the proposed NIR-activated miRNA
sensing strategy will add to the advancement for bioanalysis in living
systems, which is of crucial importance in the diagnosis of various
human diseases, especially cancers.