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Fluorescence Activation Imaging of Cytochrome c Released from Mitochondria Using Aptameric Nanosensor
journal contribution
posted on 2015-01-21, 00:00 authored by Ting-Ting Chen, Xue Tian, Chen-Liwei Liu, Jia Ge, Xia Chu, Yingfu LiWe have developed an aptameric nanosensor
for fluorescence activation
imaging of cytochrome c (Cyt c). Fluorescence imaging tools that enable
visualization of key molecular players in apoptotic signaling are
essential for cell biology and clinical theranostics. Cyt c is a major
mediator in cell apoptosis. However, fluorescence imaging tools allowing
direct visualization of Cyt c translocation in living cells have currently
not been realized. We report for the first time the realization of
a nanosensor tool that enables direct fluorescence activation imaging
of Cyt c released from mitochondria in cell apoptosis. This strategy
relies on spatially selective cytosolic delivery of a nanosensor constructed
by assembly of a fluorophore-tagged DNA aptamer on PEGylated graphene
nanosheets. The cytosolic release of Cyt c is able to dissociate the
aptamer from graphene and trigger an activated fluorescence signal.
The nanosensor is shown to exhibit high sensitivity and selectivity,
rapid response, large signal-to-background ratio for in vitro, and intracellular detection of Cyt c. It also enables real-time
visualization of the Cyt c release kinetics and direct identification
of the regulators for apoptosis. The developed nanosensor may provide
a very valuable tool for apoptotic studies and catalyze the fundamental
interrogations of Cyt c-mediated biology.