3 research outputs found
Self-illuminating NIR-II bioluminescence imaging probe based on silver sulfide quantum dots
Bioluminescence (BL) imaging has
emerged to tackle the
potential
challenges of fluorescence (FL) imaging including the autofluorescence
background, inhomogeneous illumination over a wide imaging field,
and the light-induced overheating effect. Taking advantage of the
bioluminescence resonance energy transfer (BRET) mechanism between
a conventional luciferin compound and a suitable acceptor, the visible
light of the former can be extended to photons with longer wavelengths
emitting from the latter. Although BRET-based self-illuminating imaging
probes have already been prepared, employing potentially cytotoxic
elements as the acceptor with the emission wavelengths which hardly
reach the first near-infrared (NIR-I) window, has limited their applications
as safe and high performance in vivo imaging agents.
Herein, we report a biocompatible, self-illuminating, and second near-infrared
(NIR-II) emissive probe to address the cytotoxicity concerns as well
as improve the penetration depth and spatiotemporal resolution of
BL imaging. To this end, NanoLuc luciferase enzyme molecules were
immobilized on the surface of silver sulfide quantum dots to oxidize
its luciferin substrate and initiate a single-step BRET mechanism,
resulting in NIR-II photons from the quantum dots. The resulting dual
modality (BL/FL) probes were successfully applied to in vivo tumor imaging in mice, demonstrating that NIR-II BL signals could
be easily detected from the tumor sites, giving rise to ∼2
times higher signal-to-noise ratios compared to those obtained under
FL mode. The results indicated that nontoxic NIR-II emitting nanocrystals
deserve more attention to be tailored to fill the growing demands
of preparing appropriate agents for high quality BL imaging
Durable Anti-Icing Coatings Based on Self-Sustainable Lubricating Layer
A versatile, convenient, and cost-effective
method that can be
used for grafting anti-icing materials onto different surfaces is
highly desirable. Based on mussel-inspired chemistry, the anti-icing
coating with extremely low ice adhesion is enabled by constructing
a self-sustainable lubricating layer, achieved via modifying solid
substrates with a highly hydrophilic conjugate of polyÂ(acrylic acid)–dopamine.
Both unfreezable and freezable water remain liquidlike at subzero
conditions and synergistically fulfill the role of lubrication for
reducing the ice adhesion. The anti-icing coatings show excellent
stability in harsh environments and durability after the cross-linking.
More importantly, this coating can be applied to various substrates
and is of great promise for practical applications
Size Controllable, Transparent, and Flexible 2D Silver Meshes Using Recrystallized Ice Crystals as Templates
Ice templates have been widely utilized
for the preparation of porous materials due to the obvious advantages,
such as environmentally benign and applicable to a wide range of materials.
However, it remains a challenge to have controlled pore size as well
as dimension of the prepared porous materials with the conventional
ice template, since it often employs the kinetically not-stable growing
ice crystals as the template. For example, there is no report so far
for the preparation of 2D metal meshes with tunable pore size based
on the ice template, although facile and eco-friendly prepared metal
meshes are highly desirable for wearable electronics. Here, we report
the preparation of 2D silver meshes with tunable mesh size employing
recrystallized ice crystals as templates. Ice recrystallization is
a kinetically stable process; therefore, the grain size of recrystallized
ice crystals can be easily tuned, <i>e.g.</i>, by adding
different salts and changing the annealing temperature. Consequently,
the size and line width of silver meshes obtained after freeze-drying
can be easily adjusted, which in turn varied the conductivity of the
obtained 2D silver film. Moreover, the silver meshes are transparent
and display stable conductivity after the repeated stretching and
bending. It can be envisioned that this approach for the preparation
of 2D conducting films is of practical importance for wearable electronics.
Moreover, this study provides a generic approach for the fabrication
of 2D meshes with a controllable pore size