Uniform core-shell Pd@IRMOF-3 nanostructures, where single Pd nanoparticle core is surrounded by amino-functionalized IRMOF-3 shell, are prepared by a facile mixed solvothermal method. When used as multifunctional catalysts, the Pd@IRMOF-3 nanocomposites exhibit high activity, enhanced selectivity, and excellent stability in the cascade reaction. Both experimental evidence and theoretical calculations reveal that the high catalytic performance of Pd@IRMOF-3 nanocomposites originates from their unique core-shell structures.

Noble-metal nanoparticles (NPs) (such as Au, Ag, Pd, and Pt) have been the subject of intense research because their unique physiochemical properties are different from those of their bulk counterparts [1] and various applications are anticipated in sensing, [2] imaging, [3] cancer therapy, [4] optical data storage, [5] and catalysis. [6] However, it is well known that free noble-metal NPs have high surface energies and tend to aggregate and fuse; as a result the intriguing properties observed for the NPs disappear and difficulties arise for longterm storage, processing, and applications. Therefore, great efforts have been devoted to develop novel strategies to stabilize NPs, [7] and the most common approach is to coat noble-metal NPs with either organic or inorganic shells. These shells not only endow NPs with high stability but also offer them additional functionalities. As an example, in addition to good stability and biocompatibility, the mesoporous silica shells that are currently broadly used have high surface area and tunable pore size and volume, which can accommodate analytes and drug molecules. [7, 8] Unfortunately, the amorphous structure of silica and its own characteristics determine that it may be used only as a carrier, stabilizer, and ligand linker. In order to break through the limitations and develop a wide range of applications, it is necessary to search for new types of shell materials that not only have properties similar to those of porous silica but also impart new functionalities.In addition to high specific surface area and tunable pore size and volume, metal-organic frameworks (MOFs) have many exciting characteristics including structural adaptivity and flexibility, ordered crystalline pores, and multiple coordination sites, and offer various functions such as chemical separation, [9] gas storage, [10] drug delivery, [11] sensing, [12] and catalysis, [13] which originate from the limitless choice of building blocks. [14] Recently, MOFs have been used as functional materials to fabricate nanostructures with noble-metal NPs by either embedding NPs in the MOF matrices or encapsulating NPs within the MOF layers. [15] Nevertheless, effective control over the dispersibility of NPs within MOFs as well as the morphology and size of the composite products still presents significant challenges. For example, to our knowledge, there are few reports about the construction of well-defined core-shell noble-metal@MOF NPs, [15f,g] and none on the successful synthesis of core-shell noble-metal@-

The oxygen reduction reaction (ORR) is one of the key steps in clean and efficient energy conversion techniques such as in fuel cells and metal-air batteries; however, several disadvantages of current ORRs including the kinetically sluggish process and expensive catalysts hinder mass production of these devices. Herein, we develop carbonized nanoparticles, which are derived from monodisperse nanoscale metal organic frameworks (MIL-88B-NH3), as the high performance ORR catalysts. The onset potential and the half-wave potential for the ORR at these carbonized nanoparticles is up to 1.03 and 0.92 V (vs RHE) in 0.1 M KOH solution, respectively, which represents the best ORR activity of all the non-noble metal catalysts reported so far. Furthermore, when used as the cathode of the alkaline direct fuel cell, the power density obtained with the carbonized nanoparticles reaches 22.7 mW/cm2, 1.7 times higher than the commercial Pt/C catalysts.

A novel and general method is proposed to construct three-dimensional graphene/metal oxide nanoparticle hybrids. For the first time, it is demonstrated that this graphene-based composite with open pore structures can be used as the high-performance capacitive deionization (CDI) electrode materials, which outperform currently reported materials. This work will offer a promising way to develop highly effective CDI electrode materials.

Core-shell upconversion nanoparticle@metal-organic framework (UCNP@MOF) nanostructures are constructed by coating hexagonal NaYF4 :Yb,Er nanoparticle (NP) cores with amino-functionalized iron carboxylate MOF shells. These nanostructures combine the near-infrared optical property of the UCNP cores and the T2 -magnetic response (MR) imaging property of the MOF shells. After surface modification, the core-shell nanostructures are demonstrated as high-resolution nanoprobes for targeted luminescence/MR imaging both in vitro and in vivo.

Combination therapy that could better balance immune activation and suppressive signals holds great potential in cancer immunotherapy. Herein, we serendipitously found that the pH-responsive nanovesicles (pRNVs) self-assembled from block copolymer polyethylene glycol-b-cationic polypeptide can not only serve as a nanocarrier but also cause immunogenic cell death (ICD) through preapoptotic exposure of calreticulin. After coencapsulation of a photosensitizer, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) and an indoleamine 2,3-dioxygenase inhibitor, indoximod (IND), pRNVs/HPPH/IND at a single low dose elicited significant antitumor efficacy and abscopal effect following laser irradiation in a B16F10 melanoma tumor model. Treatment efficacy attributes to three key factors: (i) singlet oxygen generation by HPPH-mediated photodynamic therapy (PDT); (ii) increased dendritic cell (DC) recruitment and immune response provocation after ICD induced by pRNVs and PDT; and (iii) tumor microenvironment modulation by IND via enhancing P-S6K phosphorylation for CD8+ T cell development. This study exploited the nanocarrier to induce ICD for the host’s immunity activation. The “all-in-one” smart nanovesicles allow the design of multifunctional materials to strengthen cancer immunotherapy efficacy.

Biocatalytic reactions in living cells involve complex transformations in the spatially confined microenvironments. Inspired by biological transformation processes, we demonstrate effective biocatalytic cascade driven photodynamic therapy in tumor-bearing mice by the integration of an artificial enzyme (ultrasmall Au nanoparticles) with upconversion nanoparticles (NaYF 4 @NaYb 0.92 F 4 :Er 0.08 @NaYF 4 )zirconium/iron porphyrin metal−organic framework core−shell nanoparticles (UMOF NPs) which act as biocatalysts and nanoreactors. The construction of core−shell UMOF NPs are realized by using a unique "solventassisted self-assembly" method. The integration of ultrasmall AuNPs on the UMOFs matrix leads to glucose depletion, providing Au-mediated cancer therapy via glucose oxidase like catalytic activity. Meanwhile, the UMOF matrix acts as a nearinfrared (NIR) light photon-activated singlet oxygen generator through a continuous supply of oxygen via hydrogen peroxide decomposition upon irradiation. Such kinds of biocatalysts offer exciting opportunities for biomedical, catalytical ,and energy applications.

The combination of reactive oxygen species (ROS)-involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) holds great promise for enhancing ROS-mediated cancer treatment. Herein, we reported an in situ polymerized hollow mesoporous organosilica nanoparticle (HMON) biocatalysis nanoreactor to integrate the synergistic effect of PDT/CDT for enhancing ROSmediated pancreatic ductal adenocarcinoma treatment. HPPH photosensitizer was hybridized within the framework of HMON via an "in situ framework growth" approach. Then, the hollow cavity of HMONs was exploited as a nanoreactor for "in situ polymerization" to synthesize the polymer containing thiol groups, thereby enabling the immobilization of ultrasmall gold nanoparticles, which behave like glucose oxidase-like nanozyme, converting glucose into H 2 O 2 to provide self-supplied H 2 O 2 for CDT. Meanwhile, Cu 2+ -tannic acid complexes were further deposited on the surface of HMONs (HMON-Au@Cu-TA) to initiate Fenton-like reaction to covert the self-supplied H 2 O 2 into •OH, a highly toxic ROS. Finally, collagenase (Col), which can degrade the collagen I fiber in the extracellular matrix (ECM), was loaded into HMON-Au@Cu-TA to enhance the penetration of HMONs and O 2 infiltration for enhanced PDT. This study provides a good paradigm for enhancing ROS-mediated anti-tumor efficacy. Meanwhile, this research offers a new method to broaden the application of silica based nanotheranostics.