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@-

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Plasmonic metal nanoparticles attract intense research attention because of their fascinating surface plasmon resonance properties and their potential applications in diverse fields. Here, some of the recent research efforts on the synthesis and applications of plasmonic metal nanoparticles are highlighted. Starting from the colloidal synthesis of metal nanoparticles, various shaped silver and gold nanostructures are discussed. The applications of plasmonic nanoparticles in photocatalysis, surface-enhanced Raman spectroscopy (SERS), and devices are used as excellent examples showcasing the advantages of these nanoparticles. The report closes with a brief summary and discussion on the challenges and future direction in this research field.

Core-shell Ag@ZIF-8 nanowires, where single Ag nanowires are coated with uniform zeolitic-imidazolate-framework-8 (ZIF-8) shells, successfully realize renewable adsorptive separation of low concentrations of butanol from an aqueous medium under solar light irradiation by taking advantage of the exceptional adsorption capability of the ZIF-8 shells toward butanol and the unique plasmonic photothermal effect of the Ag nanowire cores. Impressively, the high separation efficiency is maintained as almost unchanged, even after 10 adsorption/desorption cycles.

The morphology of Pt−Au bimetal nanostructures plays an important role in enhancing the catalytic capability, catalytic stability and utilization efficiency of the platinum. We designed and successfully prepared Au@Pt nanoparticles (NPs) through an economical, surfactant-free and efficient method of seed-mediated growth. The Au@Pt NPs displayed electrochemical performances superior to those of commercial Pt/C catalysts because their agglomeration was prevented and exhibited better long-term stability with respect to methanol oxidation in acidic media by efficiently removing intermediates. Among the obtained Au@Pt NPs, Au90@Pt10 NPs exhibited the most significantly enhanced catalytic performance for the methanol oxidation reaction (MOR). Their mass and electrochemically active surface area (ECSA)-normalized current densities are approximately 3.9 and 4.6 times higher than those of commercial Pt/C catalysts, respectively. The oxidation current densities of the Au90@Pt10 NPs are approximately 1.8 times higher than those of commercial Pt/C catalysts after 4000 s of continuous measurement because the small Pt NPs grown on the surface of the Au90@Pt10 NPs were effectively stabilized by the Au metal support. This approach may be a facile method for the synthesis of self-supported bimetallic nanostructures, which is of great significance for the development of high performance electrocatalysts and sensors.

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A facile and effective way for the preparation of nano-sized Fe3O4@graphene yolk-shell nanoparticles via a hydrothermal method is developed. Moreover, the targeting properties of the materials for anticancer drug (doxorubicin hydrochloride) delivery are investigated. Excitingly, these hybrid materials possess favorable dispersibility, good superparamagnetism (the magnetic saturation value is 45.740 emu g(-1)), high saturated loading capacity (2.65 mg mg(-1)), and effective loading (88.3%). More importantly, the composites exhibit strong pH-triggered drug release response (at the pH value of 5.6 and 7.4, the release rate was 24.86% and 10.28%, respectively) and good biocompatibility over a broad concentration range of 0.25-100 μg mL(-1) (the cell viability was 98.52% even at a high concentration of 100 μg mL(-1)) which sheds light on their potentially bright future for bio-related applications.

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