6 research outputs found
Functional Near Infrared-Emitting Cr<sup>3+</sup>/Pr<sup>3+</sup> Co-Doped Zinc Gallogermanate Persistent Luminescent Nanoparticles with Superlong Afterglow for <i>in Vivo</i> Targeted Bioimaging
Near infrared (NIR)-emitting persistent
luminescent nanoparticles
(PLNPs) have great potential for <i>in vivo</i> bioimaging
with the advantages of no need for <i>in situ</i> excitation,
high signal-to-noise ratio, and deep tissue penetration. However,
functional NIR-emitting PLNPs with long afterglow for long-term <i>in vivo</i> imaging are lacking. Here, we show the synthesis
of NIR-emitting long-persistent luminescent nanoparticles (LPLNPs)
Zn<sub>2.94</sub>Ga<sub>1.96</sub>Ge<sub>2</sub>O<sub>10</sub>:Cr<sup>3+</sup>,Pr<sup>3+</sup> by a citrate sol–gel method in combination
with a subsequent reducing atmosphere-free calcination. The persistent
luminescence of the LPLNPs is significantly improved via codoping
Pr<sup>3+</sup>/Cr<sup>3+</sup> and creating suitable Zn deficiency
in zinc gallogermanate. The LPLNP powder exhibits bright NIR luminescence
in the biological transparency window with a superlong afterglow time
of over 15 days. A persistent energy transfer between host and Cr<sup>3+</sup> ion in the LPLNPs is observed and its mechanism is discussed.
PEGylation greatly improves the biocompatibility and water solubility
of the LPLNPs. Further bioconjugation with cÂ(RGDyK) peptide makes
the LPLNPs promising for long-term <i>in vivo</i> targeted
tumor imaging with low toxicity
Fast room-temperature hydrogenation of nitroaromatics on Pd nanocrystal-boron cluster/graphene oxide nanosheets
The reduction of nitroaromatics to aminoaromatics is essential for fine chemical production and effective sewage treatment. However, the activity of an external catalyst is essential for the reaction. In this study, Pd nanocrystals were anchored in situ on two-dimensional graphene oxide (GO), which acted as a catalyst support with high specific surface area. The oxygen-containing groups on the surface of GO bonded to the functionally rich boron clusters through hydrogen bonding interactions. A mildly reducible closed-dodecahydrododecaboric acid anion cluster (closo‑[B12H12]2–) was employed as the target site. The mild reducibility of closo‑[B12H12]2– resulted in a wide dispersion of ultrafine Pd nanocrystals on GO. Under ambient conditions, Pd/BGO rapidly hydrogenated nitroaromatics, such as 4-nitrophenol, to aminoaromatics with approximately 100% efficiency. Moreover, Pd/BGO retained its high catalytic activity for the hydrogenation/reduction of 4-nitrophenol after five catalytic cycles. Therefore, Pd/BGO could be a promising and economically viable candidate for various practical applications. The proposed innovative preparation strategy and highly efficient catalytic activity suggested the effective performance of closo‑[B12H12]2– as nanometal nucleation target sites. In addition to providing an alternate route for preparing supported nanometals, this study presents a stable and efficient catalyst for the hydrogenation of nitroaromatics
Gadolinium Complexes Functionalized Persistent Luminescent Nanoparticles as a Multimodal Probe for Near-Infrared Luminescence and Magnetic Resonance Imaging <i>in Vivo</i>
The development of multimodal nanoprobes
that combined properties
of near-infrared (NIR) fluorescence and magnetic resonance imaging
(MRI) within a single probe is very important for medical diagnosis.
The NIR-emitting persistent luminescent nanoparticles (PLNPs) are
ideal for optical imaging owing to no need for in situ excitation,
the absence of background noise, and deep tissue penetration. However,
no PLNP based multimodal nanoprobes have been reported so far. Here,
we report a novel multimodal nanoprobe based on the gadolinium complexes
functionalized PLNPs (GdÂ(III)-PLNPs) for <i>in vivo</i> MRI
and NIR luminescence imaging. The GdÂ(III)-PLNPs not only exhibit a
relatively higher longitudinal relaxivity over the commercial GdÂ(III)-diethylenetriamine
pentaacetic acid complexes but also keep the superlong persistent
luminescence. The prepared GdÂ(III)-PLNPs multimodal nanoprobe offers
great potential for MRI/optical imaging <i>in vivo</i>