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In this work, copper (Cu) species were used as reducing reagents in the colloidal preparation of novel cross-shaped gold (Au) nanostructures in oleylamine. The reduction rate can be controlled through an appropriate choice of Cu species to obtain Au nanocrosses of varying sizes. It was found that the presence of Cu species during the nucleation stage is crucial to the formation of a branched morphology. Further analysis revealed that the four primary branches of the Au nanocrosses grow along the110and001directions, and that secondary branched growth occurs along the111direction. First-principles calculations and phase-field models were used to rationalize the observed preferential branching and understand the morphological evolution of the nanocrosses. These unique cross-like Au nanostructures exhibit strong NIR absorption and remarkable plasmonic properties that make them promising materials for optical and biomedical applications.

Herein, we report a facile two-step approach to produce gold-incorporated copper (Cu/Au) nanostructures through controlled disproportionation of the Cu(+)-oleylamine complex at 220 °C to form copper nanowires and the subsequent reaction with Au(3+) at different temperatures of 140, 220 and 300 °C. In comparison with copper nanowires, these bimetallic Cu/Au nanostructures exhibit their synergistic effect to greatly enhance glucose oxidation. Among them, the shape-controlled Cu/Au nanotubes prepared at 140 °C show the highest electrocatalytic activity for non-enzymatic glucose sensing in alkaline solution. In addition to high sensitivity and fast response, the Cu/Au nanotubes possess high selectivity against interferences from other potential interfering species and excellent reproducibility with long-term stability. By introducing gold into copper nanostructures at a low level of 3, 1 and 0.1 mol% relative to the initial copper precursor, a significant electrocatalytic enhancement of the resulting bimetallic Cu/Au nanostructures starts to occur at 1 mol%. Overall, the present fabrication of stable Cu/Au nanostructures offers a promising low-cost platform for sensitive, selective, reproducible and reusable electrochemical sensing of glucose.

Thiolate-protected gold nanoclusters with high chemical stability are exploited extensively for fundamental research and utility in chosen applications. Here for the first time, the controlled destabilization of extraordinarily stable thiolated gold clusters for the growth of single-crystalline gold nanoparticles (AuNPs) is demonstrated, which was achieved simply via the oxidation of surface-protecting thiolates into disulfides by hydrogen peroxide under basic condition. By combining with our experimental observations over the entire destabilization and growth process, the new growth mechanism from clusters to AuNPs is revealed by density functional theory (DFT) calculations. It is found that the size of AuNPs decreases with the increase of hydrogen peroxide concentration due to the generation of more nuclei at the higher hydrogen peroxide concentrations. In addition, the preparation of AuNPs is tuned by changing the concentration of hydrogen peroxide, and they are self-assembled into microspheres via an evaporation-mediated process, which can induce strong plasmonic coupling between adjacent AuNPs for ultrasensitive surface-enhanced Raman scattering detection. The present work demonstrates a facile route to functionalize and engineer AuNPs via controlling the reaction conditions and the ratio of precursors, and thus bring new possibilities for using more clusters as precursors to construct novel nano/microstructures for various applications.

Various metal (Ag, Au, and Pt)@thiol-functionalized silica (SiO2-SH) nanoparticles (NPs) are successfully prepared at room temperature by a facile, efficient, functional, universal and scalable coating process in alcohol-free aqueous solution using pre-hydrolyzed 3-(mercaptopropyl)trimethoxysilane (MPTMS). The controlled pre-hydrolysis of the silane precursor in water and the consecutive condensation processes are the key to achieve the effective and uniform silica coating on metal NPs in aqueous solution. The thickness of the silica shell is tuned by simply varying the coating time. The silica shell can act as an effective protecting layer for Ag NPs in Ag@SiO2-SH NPs under conditions for silica coating in aqueous solution; however, it leads to a directional dissolution of Ag NPs in a more strongly basic ammonia solution. The environmentally friendly silica coating process in water is also applied to prepare highly surface-enhanced Raman scattering (SERS)-active Ag@SiO2-SH NPs with different types of Raman molecules for highly sensitive SERS-based applications in various fields.

A precisely controlled destabilization of gold thiolate clusters is demonstrated to grow 12 {110}-faceted gold dodecahedra with greatly enhanced catalytic capability, and reveal the growth mechanism by DFT simulations. This greatly advances our understanding of nanocrystal growth and opens a new window for controlling the dissociation of clusters to produce nanocrystals with specific shapes.

The preparation of vertically or horizontally aligned self-assemblies of CoP nanowires is demonstrated for the first time by aging them in the reaction solution for a sufficient time at 20 or 0 °C. This strategy opens up a way for exploring the controlled self-assembly of various highly anisotropic nanostructures into long-range ordered structures with collective properties.

The first use of non-centrosymmetric Janus Au-TiO(2) photocatalysts in efficient, plasmon-enhanced visible-light hydrogen generation is demonstrated. The intense localization of plasmonic near-fields close to the Au-TiO(2) interface, coupled with optical transitions involving localized electronic states in amorphous TiO(2) brings about enhanced optical absorption and the generation of electron-hole pairs for photocatalysis.

A IO N Silk has been a highly prized material since its discovery a few thousand years ago, with a current annual industrial output of approximately 30 billion US dollars in China alone. [ 1 , 2 ] In silk industry, the outer layer of silk (sericin) needs to be removed in order to use the core of silk (fi broin) that has excellent mechanical properties combined with luster, smoothness, and comfort. To impart color to the fi nished products, silk fi broin is subjected to the dyeing process including steps to remove excess dye molecules and to restore the properties of silk that are altered due to the harsh conditions involved in the process. [ 3 ] Here, we demonstrate an in vivo uptake of dyes into domesticated silkworms, leading to the direct production of intrinsically colored silk by the silkworms. The biological incorporation of dyes into silk fi broin is a greener method of producing colored silk because it eliminates the need for an external dyeing process, along with the resources (water, energy, additional chemicals) and post-treatments associated with it. A series of fl uorescent dyes were successfully used as model compounds to investigate and understand their selective uptake into fi broin or sericin through fl uorescence imaging and spectroscopic quantifi cation. A better understanding of the molecular factors that determine the uptake of substances into silk fi broin was established to select and design appropriate molecules for producing intrinsically colored and luminescent silk fi broin, i.e., by controlling the structure-dependent hydrophobicity and self-assembly capability of these molecules. In addition to the production of intrinsically colored silk for textile applications, the current work also results in a biocompatible and luminescent silk scaffold that allows better visualization of cells and monitoring of the scaffold performance over time. When applied to other compounds with similar molecular properties, this process can potentially lead to functional silk for various biomedical applications including tissue engineering and bioelectronic, bio-optic, and biomicrofl uidic devices. [ 4–6 ]

Copper nanostructures with a high yield are synthesized by a controlled disproportionation of CuCl in oleylamine reaction medium without the involvement of strong reducing agents adopted in conventional approaches. The highest copper yield (50%), a maximum theoretical value, is obtained by optimizing both the initial amount of CuCl added to the reaction medium and the reaction temperature. A potential use of the copper nanostructures in greatly enhancing thermal conductivity of a hydrated CaCl2·6H2O salt phase change material (PCM) is further demonstrated. A high thermal conductivity enhancement of the PCM (>50%) is achieved by doping a small amount (

Highly emissive and air-stable AgInS2–ZnS quantum dots (ZAIS QDs) with quantum yields of up to 20% have been successfully synthesized directly in aqueous media in the presence of polyacrylic acid (PAA) and mercaptoacetic acid (MAA) as stabilizing and reactivity-controlling agents. The as-prepared water-dispersible ZAIS QDs are around 3 nm in size, possess the tetragonal chalcopyrite crystal structure, and exhibit long fluorescence lifetimes (>100 ns). In addition, these ZAIS QDs are found to exhibit excellent optical and colloidal stability in physiologically relevant pH values as well as very low cytotoxicity, which render them particularly suitable for biological applications. Their potential use in biological labelling of baculoviral vectors is demonstrated.