Near-infrared (NIR) persistent luminescence
nanoparticles (PLNPs),
possessing unique NIR PL properties, have recently emerged as important
materials for a wide variety of applications in chemistry and biology,
for which they must endure high-temperature solid-state annealing
reactions and subsequent complicated physical post-treatments. Herein,
we report on a first direct aqueous-phase chemical synthesis route
to NIR PLNPs and present their enhanced in vivo renewable
NIR PL. Our method
leads to monodisperse PLNPs as small as ca. 8 nm. Such sub-10 nm nanocrystals
are readily dispersed and functionalized, and can form stable colloidal
solutions in aqueous solution and cell culture medium for biological
applications. Under biotissue-penetrable red-light excitation, we
found that such nanocrystals possess superior renewable PL photoluminescence in vitro and in vivo compared to their
larger counterparts currently
made by existing methods. We believe that this solid-state-reaction-free
chemical approach overcomes the current key roadblock in regard to
PLNP development, and thus will pave the way to broad use of these
advanced miniature “luminous pearls” in photonics and
biophotonics.
Electrocatalytic C−N bond coupling to convert CO2 and N2 molecules into urea under ambient conditions is a promising alternative to harsh industrial processes. However, the adsorption and activation of inert gas molecules and then the driving of the C–N coupling reaction is energetically challenging. Herein, novel Mott–Schottky Bi‐BiVO4 heterostructures are described that realize a remarkable urea yield rate of 5.91 mmol h−1 g−1 and a Faradaic efficiency of 12.55 % at −0.4 V vs. RHE. Comprehensive analysis confirms the emerging space–charge region in the heterostructure interface not only facilitates the targeted adsorption and activation of CO2 and N2 molecules on the generated local nucleophilic and electrophilic regions, but also effectively suppresses CO poisoning and the formation of endothermic *NNH intermediates. This guarantees the desired exothermic coupling of *N=N* intermediates and generated CO to form the urea precursor, *NCON*.
Electrocatalytic C-N coupling reaction by co-activation of both N2 and CO2 molecules under ambient conditions to synthesis valuable urea opens a new avenue for sustainable development, while the actual catalytic...
Lanthanide-doped photon upconverting
nanomaterials are emerging
as a new class of imaging contrast agents, providing numerous unprecedented
possibilities in the realm of biomedical imaging. Because of their
ability to convert long-wavelength near-infrared excitation radiation
into shorter-wavelength emissions, these nanomaterials are able to
produce assets of low imaging background, large anti-Stokes shift,
as well as high optical penetration depth of light for deep tissue
optical imaging or light-activated drug release and therapy. The aim
of this review is to line up some issues associated with conventional
fluorescent probes, and to address the recent advances of upconverting
nanoparticles (UCNPs) as a solution to multiscale biological imaging
applications.
Precisely fabricated frustrated Lewis pairs in the Ni3(BO3)2 nanocrystal achieve integration of the active sites and effective electrocatalytic C–N bond coupling to synthesize urea.
Near-infrared (NIR) persistent phosphor ZnGa2O4:Cr3+ (ZGC) has unique deep-tissue rechargeable afterglow properties. However, the current synthesis leads to agglomerated products with irregular morphologies and wide size distributions. Herein, we report on in vivo rechargeable mesoporous SiO2/ZnGa2O4:Cr3+ (mZGC) afterglow NIR-emitting nanocomposites that are made by a simple, one-step mesoporous template method. At less than 600 °C, pores in mesoporous silica nanoparticles (MSNs) act as nanoreactors to generate in situ ZnGa2O4:Cr3+ NIR-persistent phosphors. The as-synthesized mZGC preserves defined size, morphology, and mesoporous nanostructure of the MSNs. The persistent luminescence of the as-synthesized mZGC is recharged in a simulated deep-tissue environment (e.g., ≈8 mm pork slab) in vitro by using red light (620 nm). Moreover, mZGC can be repeatedly activated in vivo for persistent luminescence imaging in a live mouse model by using white LED as a light source. Our concept of utilizing mesoporous silica as nanoreactor to fabricate ZGC PL nanoparticles with controllable morphology and preserved porous nanostructure paves a new way to the development and the wide application of deep tissue rechargeable ZGC in photonics and biophotonics.
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