Functional Near Infrared-Emitting Cr³⁺/Pr³⁺ 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_2.94Ga_1.96Ge₂O₁₀:Cr³⁺,Pr³⁺ 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 Pr³⁺/Cr³⁺ 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 Cr³⁺ 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 c­(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 (Gd­(III)-PLNPs) for <i>in vivo</i> MRI and NIR luminescence imaging. The Gd­(III)-PLNPs not only exhibit a relatively higher longitudinal relaxivity over the commercial Gd­(III)-diethylenetriamine pentaacetic acid complexes but also keep the superlong persistent luminescence. The prepared Gd­(III)-PLNPs multimodal nanoprobe offers great potential for MRI/optical imaging <i>in vivo</i>