Measurement of 16O5+ Induced L X-Ray Production Cross Sections for Gold

The characteristic Ll, Lα, Lβ and Lγx-rays of Au and energy shifts produced by 20–50MeV 16O5+ beams on a thick Au ilm are measured with a Si (Li) detector. Cross-section ratios of σ(Ll)/σ(Lα), σ(Lβ)/σ(Lα) andσ(Lγ)/σ(Lα) versus O5+ energy show that consistent calculations yield considerably better agreements. Energy shifts Ll, Lα, Lβ and Lγ x-rays of Au target increase with more incidence energy. The main application for these measurements is multi-element trace analysis through particle induced x-ray emission.

Preparation and Optical Properties of Gold Nanowire Arrays

Gold nanowires with diameters (d) between,15 run and 200 urn and with length/diameter ratio of 700 were prepared in ion-track templates with electrode position method. The morphology and crystal structure of the gold nanowires were Studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The 200 nm (d) gold nanowires preferred orientation along the [100] direction were formed at the deposition voltage of 1.5 V (Without reference electrode). The optical properties of gold nanowire arrays embedded in ion-track templates were studied by UV-Vis spectrophotometer. There was a strong absorption peak at 539 nm for 45 nm (d) gold nanowire arrays. With the diameter of gold nanowires increasing, the absorption peak shifted to the longer wavelength. At last, the result was discussed combined with surface plasmon resonance of gold nanoparticles.

Gold Nanoparticle-based Colorimetric Sensor for pH Sensing

We present a newly designed colormetric sensor sensitive to pH value based on a gold nanocomposite composed of gold nanoparticles and pH-sensitive polymer{dodecylthioether end functionalized poly[2-(diethlamino) ethyl methacrylate], poly(DEAEMA)-DDT}. We have shown that this design can produce stable GNP precipitate under weakly basic condition(pH=7.5) and this precipitate can be dispersed in acidic solution(pH=4.0), due to the 2-(diethylamino) ethyl methacrylate protonated by H+.

One-step preparation of hybrid materials of polyacrylamide networks and gold nanoparticles

Hybrid materials of polyacrylamide networks and gold nanoparticles were prepared by directly heating an aqueous solution containing HAuCl4, acrylamide, N,N'-methylenebisacrylamide, and sodium sulfite (Na2SO3). Acrylamide, N,N'-methylenebisacrylamide, and Na2SO3 were used as monomers, crosslinking agent, and initiator, respectively.

The fragmentation of gold nanoparticles induced by small biomolecules

Spherical gold nanoparticles (3-5 nm) undergo a surprising fragmentation without extra energy imput and are converted into ultrasmall particles (less than 1.5 nm), which is a direct result of electron transfer between gold nanoparticles and cysteine.

Enhanced resonance light scattering based on biocatalytic growth of gold nanoparticles for biosensors design

The biocatalytic growth of gold nanoparticles (Au-NPs) has been employed in the design of new optical biosensors based on the enhanced resonance light scattering (RLS) signals. Both absorption spectroscopy and transmission electron microscopy (TEM) analysis revealed Au-NP seeds could be effectively enlarged upon the reaction with H2O2, an important metabolite that could be generated by many biocatalytic reactions.

A sensitive NADH and glucose biosensor tuned by visible light based on thionine bridged carbon nanotubes and gold nanoparticles multilayer

A NADH and glucose biosensor based on thionine cross-linked multiwalled carbon nanotubes (MWNTs) and Au nanoparticles (Au NPs) multilayer functionalized indium-doped tin oxide (ITO) electrode were presented in this paper. The effect of light irradiation on the enhancement of bioelectrocatalytic processes of the biocatalytic systems by the photovoltaic effect was investigated.

Facile electrochemical approach to fabricate hierarchical flowerlike gold micro structures: Electrodeposited superhydrophobic surface

A templateless, surfactantless, electrochemical approach is proposed to directly fabricate hierarchical flowerlike gold microstructures (HFGMs) on an indium tin oxide (ITO) substrate. The as-prepared HFGMs have been characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and cyclic voltammetry.

Surface-enhanced Raman scattering from surfactant-free 3D gold nanowire networks substrates

A useful method for the fabrication of three-dimensional gold nanowire networks based on the chemical reduction of HAuCl4 with trisodium citrate was presented. The coverage of the 3D gold nanowire networks was tunable by altering precursor concentration. The as-prepared 3D gold nanowire networks could be used as surface-enhanced Raman scattering (SERS) substrates and examined by 4-aminothiophenol (4-ATP) as a probe molecules.

Detection of neurotransmitters by a light scattering technique based on seed-mediated growth of gold nanoparticles

A simple light scattering detection method for neurotransmitters has been developed, based on the growth of gold nanoparticles. Neurotransmitters (dopamine, L-dopa, noradrenaline and adrenaline) can effectively function as active reducing agents for generating gold nanoparticles, which result in enhanced light scattering signals. The strong light scattering of gold nanoparticles then allows the quantitative detection of the neurotransmitters simply by using a common spectrofluorometer.