Mesoporous Metal Sponges Produced by Explosive Decomposition.

The formation of mesoporous gold sponges by explosive decomposition of 'knallgold' (also known as 'fulminating' gold) is studied. Proof-of-principle experiments are conducted and then the phenomena are further investigated using 'toy physics' molecular dynamics simulations. The simulations invoked various ratios of a volatile Lennard-Jones element G and a noble metal element N.

Thermal Effect during Laser-Induced Plasmonic Heating of Polyelectrolyte-Coated Gold Nanorods in Well Plates.

We examined the generation and transfer of heat when laser irradiation is applied to water containing a suspension of gold nanorods coated with different polyelectrolytes. The ubiquitous well plate was used as the geometry for these studies. The predictions of a finite element model were compared to experimental measurements.

Ultra-small cobalt particles embedded in titania by ion beam synthesis: Additional datasets including electron microscopy, neutron reflectometry, modelling outputs and particle size analysis.

This Data-in-brief article includes datasets of electron microscopy, polarised neutron reflectometry and magnetometry for ultra-small cobalt particles formed in titania thin films via ion beam synthesis. Raw data for polarised neutron reflectometry, magnetometry and the particle size distribution are included and made available on a public repository. Additional elemental maps from scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) are also presented.

Comparison of Single- and Mixed-Sized Gold Nanoparticles on Lateral Flow Assay for Albumin Detection.

The sensitivity and reproducibility of the lateral flow assay can be influenced by multiple factors, such as the size of gold nanoparticles (GNPs) employed. Here, we evaluated the analytical performance of single-sized and mixed-sized GNPs using a simple lateral flow assay (LFA) platform. This platform was used as a model assay to diagnose albumin levels and demonstrate the analytical performance of single-sized and mixed-sized GNPs in LFA tests.

The Quest for Zero Loss: Unconventional Materials for Plasmonics.

There has been an ongoing quest to optimize the materials used to build plasmonic devices: first the elements were investigated, then alloys and intermetallic compounds, later semiconductors were considered, and, most recently, there has been interest in using more exotic materials such as topological insulators and conducting oxides. The quality of the plasmon resonances in these materials is closely correlated with their structure and properties. In general gold and silver are the most commonly specified materials for these applications but they do have weaknesses.

Single and multiple detections of foodborne pathogens by gold nanoparticle assays.

A late detection of pathogenic microorganisms in food and drinking water has a high potential to cause adverse health impacts in those who have ingested the pathogens. For this reason there is intense interest in developing precise, rapid and sensitive assays that can detect multiple foodborne pathogens. Such assays would be valuable components in the campaign to minimize foodborne illness.

Photomechanical photochromism in a cetyltrimethylammonium isopolytungstate.

The photochromic properties of a hybrid compound comprised of the surfactant cation cetyltrimethylammonium [(CH)N(CH)] (CTA) and the isopolytungstate anion [HWO] is investigated. The compound, which has the nominal formula (CTA)[HWO]Cl·2HO, changes from white to blue when exposed to UV radiation. The sample returns to the bleached state if stored in the dark-ambient.

Heat transfer from nanoparticles for targeted destruction of infectious organisms.

Whereas the application of optically or magnetically heated nanoparticles to destroy tumours is now well established, the extension of this concept to target pathogens has barely begun. Here we examine the challenge of targeting pathogens by this means and, in particular, explore the issues of power density and heat transfer. Depending on the rate of heating, either hyperthermia or thermoablation may occur.

From Lead(II) Dithiocarbamate Precursors to a Fast Response PbS Positive Temperature Coefficient Thermistor.

PbS submicron crystals were formed by thermolysis of two different lead dithiocarbamate complexes. These precursors were readily synthesized and fully characterized, and in situ synchrotron powder diffraction experiments were performed to characterize their decomposition. The structure and purity of resultant PbS was examined using scanning electron and transmission electron microscopies, powder X-ray diffraction, and infrared spectroscopy.

Gold nanoparticles improve metabolic profile of mice fed a high-fat diet.

Background: Obesity is a high risk for multiple metabolic disorders due to excessive influx of energy, glucose and lipid, often from a western based diet. Low-grade inflammation plays a key role in the progression of such metabolic disorders. The anti-inflammatory property of gold compounds has been used in treating rheumatoid arthritis in the clinic.

Prussian Blue Nanocubes with an Open Framework Structure Coated with PEDOT as High-Capacity Cathodes for Lithium-Sulfur Batteries.

It is shown that Prussian blue analogues (PBAs) can be a very competitive sulfur host for lithium-sulfur (Li-S) batteries. Sulfur stored in the large interstitial sites of a PBA host can take advantage of reversible and efficient insertion/extraction of both Li and electrons, due to the well-trapped mobile dielectron redox centers in the well-defined host. It is demonstrated that Na Fe[Fe(CN) ] has a large open framework, and as a cathode, it both stores sulfur and acts as a polysulfide diffusion inhibitor based on the Lewis acid-base bonding effect.

Optical properties and oxidation of α-phase Ag-Al thin films.

We investigate a series of Ag-Al thin films containing up to 12 at% Al with the purpose of discovering whether these alloys would be a better choice for nanophotonic applications than pure Ag. Variable angle spectroscopic ellipsometry, AFM, x-ray diffraction and density functional theory are applied to explore and characterize the materials. Electromagnetic simulations of optical properties are used to place the results into a theoretical framework.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.

Multipolar and dark-mode plasmon resonances on drilled silver nano-triangles.

Dark-mode plasmon resonances can be excited by positioning a suitable nano-antenna above a nanostructure to couple a planar incident wave-front into a virtual point source. We explore this phenomenon using a prototypical nanostructure consisting of a silver nanotriangle into which a hole has been drilled and a rod-like nano-antenna of variable aspect ratio. Using numerical simulations, we establish the behavior of the basic drilled nanotriangle under plane wave illumination and electron beam irradiation to provide a baseline, and then add the nano-antenna to investigate the stimulation of additional dark-mode plasmon resonances.

Seed-induced growth of flower-like Au-Ni-ZnO metal-semiconductor hybrid nanocrystals for photocatalytic applications.

The combination of metal and semiconductor components in nanoscale to form a hybrid nanocrystal provides an important approach for achieving advanced functional materials with special optical, magnetic and photocatalytic functionalities. Here, a facile solution method is reported for the synthesis of Au-Ni-ZnO metal-semiconductor hybrid nanocrystals with a flower-like morphology and multifunctional properties. This synthetic strategy uses noble and magnetic metal Au@Ni nanocrystal seeds formed in situ to induce the heteroepitaxial growth of semiconducting ZnO nanopyramids onto the surface of metal cores.

Optical readout of the intracellular environment using nanoparticle transducers.

There is rapid growth in the use of multi-functional nanoparticles as transducers to probe the intracellular environment. New designs of nanoparticles can provide quantitative information at sub-cellular resolution on parameters such as pH, temperature and concentration of nicotinamide adenine dinucleotide (NADH) or selected metal ions. This new work builds on the existing practice of using nanoparticles and fluorescent dyes to provide enhanced microscopic images of cells, but goes beyond it by adding new functionalities and analytical capabilities.

Effect of precursor stoichiometry on the morphology of nanoporous platinum sponges.

Nanoscale sponges formed by de-alloying suitable metallic alloys have a wide variety of potential applications due to their enhanced catalytic, optical, and electrochemical properties. In general, these materials have a bi-continuous, vermicular morphology of pores and ligaments with a fibrous appearance; however, other morphologies are sometimes reported. Here, we investigate how stoichiometry and process parameters control the characteristics of sponges formed from thin film precursors of AlxPt.

Charging of gold/metal oxide/gold nanocapacitors in a scanning electron microscope.

Triangular parallel-plate nanocapacitors were fabricated by a combination of microsphere lithography and physical vapor deposition. The devices were comprised of a 20 nm layer of dielectric material sandwiched between two 20 nm layers of gold. Dielectric materials with a range of relative permittivities were investigated.

Nanomedical research in Australia and New Zealand.

Although Australia and New Zealand have a combined population of less than 30 million, they have an active and interlinked community of nanomedical researchers. This report provides a synopsis and update on this network with a view to identifying the main topics of interest and their likely future trajectories. In addition, our report may also serve to alert others to opportunities for joint projects.

Zinc hydroxide sulphate and its transformation to crystalline zinc oxide.

The thermal transformation of zinc hydroxide sulphate hydrate to zinc oxide has been examined using synchrotron X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and surface area measurements. By collecting X-ray diffraction data in situ, we found that the dehydration of zinc hydroxide sulphate pentahydrate proceeded in discrete steps to form anhydrous zinc hydroxide sulphate. This compound then decomposed to a mixture of zinc oxide and a compound tentatively identified as Zn3(OH)2(SO4)2 at ~235 °C.

In vivo study of spherical gold nanoparticles: inflammatory effects and distribution in mice.

Objectives: Gold nanoparticles (AuNPs) of 21 nm have been previously well characterized in vitro for their capacity to target macrophages via active uptake. However, the short-term impact of such AuNPs on physiological systems, in particular resident macrophages located in fat tissue in vivo, is largely unknown. This project investigated the distribution, organ toxicity and changes in inflammatory cytokines within the adipose tissue after mice were exposed to AuNPs.

Zinc hydroxyacetate and its transformation to nanocrystalline zinc oxide.

The synthesis of nanocrystalline ZnO by thermal decomposition of zinc hydroxyacetate, Zn(5)(OH)(8)(CH(3)CO(2))(2)·nH(2)O, was investigated. The decomposition process was examined using X-ray diffraction, thermogravimetric analysis, mass spectrometry, electron microscopy, Brunauer-Emmett-Teller surface area analysis, and solid-state NMR spectroscopy. Intermediate Zn(5)(OH)(8)(CH(3)CO(2))(2)·nH(2)O phases form at temperatures up to 110 °C from the starting compound Zn(5)(OH)(8)(CH(3)CO(2))(2)·2H(2)O by partial dehydration.

Multimode resonances in silver nanocuboids.

A rich variety of dipolar and higher order plasmon resonances have been predicted for nanoscale cubes and parallopipeds of silver, in contrast to the simple dipolar modes found on silver nanospheres or nanorods. However, in general, these multimode resonances are not readily detected in experimental colloidal ensembles, due primarily to the usual variation of size and shape of the particles obscuring or blending the individual extinction peaks. Recently, methods have been found to prepare silver parallopipeds with unprecedented shape control by nucleating the silver onto a tightly controlled suspension of gold nanorods (Okuno, Y.

Formation of gold nanorods by a stochastic "popcorn" mechanism.

Gold nanorods have significant technological potential and are of broad interest to the nanotechnology community. The discovery of the seeded, wet-chemical synthetic process to produce them may be regarded as a landmark in the control of metal nanoparticle shape. However, the mechanism by which the initial spherical gold seeds acquire anisotropy is a critical, yet poorly understood, factor.