1 research outputs found
Dual-Mode Gold Nanocluster-Based Nanoprobe Platform for Two-Photon Fluorescence Imaging and Fluorescence Lifetime Imaging of Intracellular Endogenous miRNA
Bioimaging is widely used in various fields of modern
medicine.
Fluorescence imaging has the advantages of high sensitivity, high
selectivity, noninvasiveness, in situ imaging, and so on. However,
one-photon (OP) fluorescence imaging has problems, such as low tissue
penetration depth and low spatiotemporal resolution. These disadvantages
can be solved by two-photon (TP) fluorescence imaging. However, TP
imaging still uses fluorescence intensity as a signal. The complexity
of organisms will inevitably affect the change of fluorescence intensity,
cause false-positive signals, and affect the accuracy of the results
obtained. Fluorescence lifetime imaging (FLIM) is different from other
kinds of fluorescence imaging, which is an intrinsic property of the
material and independent of the material concentration and fluorescence
intensity. FLIM can effectively avoid the fluctuation of TP imaging
based on fluorescence intensity and the interference of autofluorescence.
Therefore, based on silica-coated gold nanoclusters (AuNCs@SiO2) combined with nucleic acid probes, the dual-mode nanoprobe
platform was constructed for TP and FLIM imaging of intracellular
endogenous miRNA-21 for the first time. First, the dual-mode nanoprobe
used a dual fluorescence quencher of BHQ2 and graphene oxide (GO),
which has a high signal-to-noise ratio and anti-interference. Second,
the dual-mode nanoprobe can detect miR-21 with high sensitivity and
selectivity in vitro, with a detection limit of 0.91 nM. Finally,
the dual-mode nanoprobes performed satisfactory TP fluorescence imaging
(330.0 μm penetration depth) and FLIM (τave = 50.0 ns) of endogenous miR-21 in living cells and tissues. The
dual-mode platforms have promising applications in miRNA-based early
detection and therapy and hold much promise for improving clinical
efficacy