Gold nanoparticles reflect different colors when exposed to light. Gold nanoparticles properties can be changed by altering their structure, shape and size. These advantages have been driving the global gold nanoparticles market in major end-use industries including electronics, sensory probes, therapeutic agents and medical applications. Gold nanoparticles are available at nano scale size ranging from 5nm to 100nm. Gold nanoparticles market has been witnessing strong growth over the last few years on account of increasing demand from medical and dentistry sector and trend is expected to continue over the forecast period. Growing application scope of nanotechnology in medical sector especially in diagnostics and imaging application is the key factor expected to drive the market over the next six years. Gold nanoparticles are used in detection of tumor cells and cancer drug delivery. These advantageous factors are expected to boost nanoparticles demand over the forecast period. Gold nanoparticles ...
TY - JOUR. T1 - Multiplexed DNA detection with DNA-functionalized silver and silver/gold nanoparticle superstructure probes. AU - Kim, Ji Young. AU - Lee, Jae-Seung. PY - 2012/1/20. Y1 - 2012/1/20. N2 - DNA-functionalized silver and silver/gold bimetallic nanoparticle superstructure probes with controllable sizes and optical properties are synthesized using monothiol DNA and dithiothreitol. The superstructures exhibit a very narrow size distribution, which can be easily controlled by balancing the ratio of dithiothreitol and DNA. These superstructures assemble reversibly in a highly cooperative manner, and are SERS active. Multiplexed colorimetric detection of DNA targets using these superstructure probes has been demonstrated to identify three different DNA target sequences that are associated with three lethal diseases, respectively.. AB - DNA-functionalized silver and silver/gold bimetallic nanoparticle superstructure probes with controllable sizes and optical properties are synthesized using ...
Tuning and controlling size, shape and surface characteristics of plasmonic gold nanoparticles can help define their photonic, catalytic, and spectroscopic properties, and therefore are crucial for the development of biosensors. This strategy is demonstrated in the present study. Gold nanostars (Au NST) chemically synthesized through a seeding approach exhibited not only Vis-NIR tunable localized surface plasmon resonance (LSPR), but also strong peroxidase-mimicking activity which can catalyse the oxidation of tetramethylbenzidine (TMB) into an oxidized chromogenic product (oxTMB). The catalytic activity of gold nanostars was found to correlate well with their size and LSPR mode, and to be strongly affected by capping ligands (i.e. poly and oligo ethylene glycol, 11-mercaptoundecanoic acid, 4-mercaptobenzoic acid). When capped with molecular binders (i.e. peptides and antibodies), the peroxidase-mimicking activity was suppressed by almost 100% under the examined conditions. However, a gold ...
The attachment of cells onto solid surfaces is a fundamental pedestal in the field of biosensors and biochips development. In this work we investigate the adhesion and survival of rat cortical neurons on positively charged surface. We bind amino-functionalized thiol (Amino-EG6-undecanethiol) on Au nanoparticles that are immobilized on surfaces with varying density. The neural cell survival and adhesion is studied on the Au nanoparticles that work as carriers for positive charges. The Au nanoparticles attachment is done by silanizing a Si/SiO2 surface with amino terminated silane (APTES) and on gold substrate by 11-MUA (11-Mercaptoundecanoic acid). Different number of positive charge on Au nanoparticles is obtained by tuning the number of density of Au nanoparticles. A comparison is made between two types of surfaces for cell survival and attachment.. The neural cells are cultured on positively charged gold nanoparticles as well as on PLL (Poly-Lysine) coated surfaces. The Characterization of the ...
A gold-nanoparticles (Au NPs)-Rhodamine 6G (Rh6G) based fluorescent sensor for detecting Hg(II) in aqueous solution has been developed. Water-soluble and monodisperse gold nanoparticles (Au NPs) has been prepared facilely and further modified with thioglycolic acid (TGA). Free Rh6G dye was strongly fluorescent in bulk solution. The sensor system composing of Rh6G and Au NPs fluoresce weakly as result of fluorescence resonance energy transfer (FRET) and collision. The fluorescence of Rh6G and Au NPs based sensor was gradually recovered due to Rh6G units departed from the surface of functionalized Au NPs in the presence of Hg(II). Based on the modulation of fluorescence quenching efficiency of Rh6G-Au NPs by Hg(II) at pH 9.0 of teraborate buffer solution, a simple, rapid, reliable and specific turn-on fluorescent assay for Hg(II) was proposed. Under the optimum conditions, the fluorescence intensity of sensor is proportional to the concentration of Hg(II). The calibration graphs are linear over the range
In the present study, we fabricated a hemoglobin/gold nanoparticle (Hb/GNP) heterolayer immobilized on the Au micro-gap to confirm H2O2 detection with a signal-enhancement effect. The hemoglobin which contained the heme group catalyzed the reduction of H2O2. To facilitate the electron transfer between hemoglobin and Au micro-gap electrode, a gold nanoparticle was introduced. The Au micro-gap electrode that has gap size of 5 µm was fabricated by conventional photolithographic technique to locate working and counter electrodes oppositely in a single chip for the signal sensitivity and reliability. The hemoglobin was self-assembled onto the Au surface via chemical linker 6-mercaptohexanoic acid (6-MHA). Then, the gold nanoparticles were adsorbed onto hemoglobin/6-MHA heterolayers by the layer-by-layer (LbL) method. The fabrication of the Hb/GNP heterolayer was confirmed by atomic force microscopy (AFM) and surface-enhanced Raman spectroscopy (SERS). The redox property and H2O2 detection of Hb/GNP on the
We present and analyze a method to improve the morphology and mechanical properties of gold thin films for use in optical sensors or other settings where good adhesion of gold to a substrate is of importance and where controlled topography/roughness is key. To improve the adhesion of thermally evaporated gold thin films, we introduce a gold deposition step on SU-8 photoresist prior to UV exposure but after the pre-bake step of SU-8 processing. Shrinkage and distribution of residual stresses, which occur during cross-linking of the SU-8 polymer layer in the post-exposure baking step, are responsible for the higher adhesion of the top gold film to the post-deposition cured SU-8 sublayer. The SU-8 underlayer can also be used to tune the resulting gold film morphology. Our promoter-free protocol is easily integrated with existing sensor microfabrication processes.
Recently, gold nanoparticles (AuNPs) are used for drug delivery in treating several neurological disorders e.g., Alzheimers disease (AD), Parkinsons disease, Stroke and trauma. In addition, use of AuNPs for diagnostic purposes in various diseases are also common in clinical medicine. However, the neurotoxic effects of AuNPs in vivo studies are not well explored. Thus, it would be interesting to examine AuNPs neurotoxicity in vivo models in relation to size related effects on brain pathology. We examined the effects of moderate doses of AuNPs of 3 different sizes (5 nm, 10 nm and 40 nm) administered either though intraperitoneally (10 mg/kg, i.p.), intravenously (5 mg/kg, i.v.), intracarotidly (2 mg/kg, i.c.a.) or intracerebroventricularly (20 µg in 20 µl, i.c.v.) in rats (Age 20 to 25 weeks). Blood-brain barrier (BBB) breakdown to Evans blue albumin (EBA 3 ml/kg, i.v.) and [131]-Iodine (100 µCi/kg, i.v.) was examined 24 h after AuNPs administration in the brain in relation to edema formation and
Americas Gold Nanoparticles Market Analysis by Type (nanorods, nanoshells , nanocages) by Application (photodynamic therapy, diagnostics, medical imaging), by End-users (Hospitals, Clinics, Dental clinics) Global Industry Analysis, Size, Share, Growth, Trends, and - Forecast to 2027. Market Synopsis of Gold nanoparticles Market Scenario. The market for Gold nanoparticles is increasing rapidly due to increasing advancement in nanotechnologies. The factors that influence the growth of Gold nanoparticles market; expanding medical diagnostics industry, increasing growth in advance healthcare technology, high advantages in medicinal imaging applications and many others. As per the American Nano Society, nanotechnology is a field of science which manages the investigation of nano size. In medical field, gold nanoparticles, titanium dioxide, zinc oxide, and calcium phosphate are significantly used nanoparticles. These particles all things considered represented a piece of the overall industry of more ...
Gold nanoparticles with sizes around 2 nm and below are being studied extensively because they exhibit novel electronic, magnetic, optical and catalytic properties. We are investigating the formation of Au-55 types of gold nanoparticles through a reduction reaction at a liquid-liquid interface. Diffuse X-ray scattering and reflectivity techniques [1] allow us to monitor the formation of gold nanoparticles at liquid-liquid interface. These techniques also provide information regarding the out-of-plane and in-plane structure of the gold nanoparticles at liquid surface and liquid-liquid interface.. In situ X-ray scattering measurements were carried out at beamline ID10B during the formation of gold nanoparticles at a toluene-water interface. The reduction reaction [2] uses an organic precursor of gold kept in the toluene layer and a reducing agent kept in the slightly alkaline water layer. As the reaction occurs through the creation of fingers from one liquid to another, the size (1 nm diameter) of ...
Nanoparticles have contributed significantly to the design of new drug delivery and targeting in cancer chemotherapy. Consequently, some of the desirable qualities of silver and gold nanoparticles have prompted their novel applications in cancer nanobiotechnology. Glioblastoma is the most common and highest grade primary brain tumors in adults. Despite limited recent advances in treatment of this neurotumor, the prognosis of patients with this tumor remains extremely poor. In this study, we have investigated the hypothesis that silver and gold nanoparticles exert differential cytotoxic effects on human astrocytoma (glioblastoma) U87 cells. Our results demonstrate silver and gold nanoparticles induced time- and concentration-related effects in lowering the survival of U87 cells. Consistent with our hypothesis, the effects induced by silver nanoparticles were much more pronounced compared to those induced by gold nanoparticles. We also found that both silver and gold nanoparticles induced changes in the
... (Gold Nanoparticle Conjugation Kits). One-Step mini kit for covalent conjugation of proteins and other amine containing ligands to 30nm gold nanoparticles. Contains enough reagents for conjugation of 10 x 40ug of protein.
... (Gold Nanoparticle Conjugation Kits). One-Step mini kit for covalent conjugation of proteins and other amine containing ligands to 20nm gold nanoparticles. Contains enough reagents for conjugation of 10 x 40ug of protein.
TY - JOUR. T1 - Measurement of adsorption constants of laccase on gold nanoparticles to evaluate the enhancement in enzyme activity of adsorbed laccase. AU - Almeida, Miguel Peixoto de AU - Quaresma, Pedro. AU - Sousa, Susana. AU - Couto, Cláudia. AU - Gomes, Inês. AU - Krippahl, Ludwig. AU - Franco, Ricardo. AU - Pereira, Eulália. N1 - Marta Giza is acknowledged for expert utilization of the UCSF Chimera package. Chimera is developed by the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco (supported by NIGMS P41-GM103311). This work was supported by (a) Unidade de Ciencias Biomoleculares Aplicadas-UCIBIO which is financed by Portuguese national funds from FCT/MEC (UID/Multi/04378/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007728); and NOVA LINCS UID/CEC/04516/2013; and (b) European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundacao para a Ciencia e Tecnologia), under ...
Global Gold Nanoparticles Market is expected to reach USD 4.86 billion by 2020, according to a new study by Grand View Research, Inc. Medical & dentistry was the largest end-use segment for the gold nanoparticles and accounted for over 50% of total demand in 2013. Growing metal nanomaterials use in medical diagnostics & imaging especially for drug delivery systems in cancer & tumor cell detection is expected to drive gold nanoparticles demand over the forecast period.. North America dominated the global gold nanoparticles market accounting for over 30% of global volume in 2013. Increasing R&D spending by individual nanotechnology companies and universities along with expanding medical diagnostics industry is expected to be the major factors driving gold nanoparticles demand in the region. Asia Pacific is estimated to witness the fastest growth at a CAGR of over 25% from 2014 to 2020. Growth of nanomaterials industry in countries including China, Taiwan, South Korea and Japan along with emergence ...
This work proposes a method for fabricating silica-coated gold (Au) nanoparticles, surface modified with poly(ethylene glycol) (PEG) (Au/SiO2/PEG), with a particle size of 54.8 nm. X-ray imaging of a mouse is performed with the colloid solution. A colloid solution of 17.9 nm Au nanoparticles was prepared by reducing Au ions (III) with sodium citrate in water at 80 °C. The method used for silica-coating the Au nanoparticles was composed of surface-modification of the Au nanoparticles with (3-aminopropyl)-trimethoxysilane (APMS) and a sol-gel process. The sol-gel process was performed in the presence of the surface-modified Au nanoparticles using tetraethylorthosilicate, APMS, water, and sodium hydroxide, in which the formation of silica shells and the introduction of amino groups to the silica-coated particles took place simultaneously (Au/SiO2-NH2). Surface modification of the Au/SiO2-NH2 particles with PEG, or PEGylation of the particle surface, was performed by adding PEG with a functional ...
Purpose: : Molecular in vivo imaging allows for diagnostic imaging, target screening, and therapeutic monitoring of disease on a molecular level, prior to evidence of pathologic changes that can be detected with conventional imaging modalities. Optical Coherence Tomography (OCT) is an imaging modality used to visualize ocular structures with high spatial resolution. We have created optimized gold nanoparticles (GNPs) which produce a strong OCT signal, beyond the background tissue OCT signal, and can fulfill the role of an exogenous OCT contrast agent. In order to achieve molecular diagnostic and therapeutic capabilities, we functionalized these GNPs with anti-VEGF antibodies, allowing for the dual purpose of molecular diagnostic imaging and therapy towards age-related macular degeneration (AMD). Methods: : GNPs with a longitudinal plasmon resonance at 840nm were synthesized using seed-mediated growth mechanism. The GNPs were covalently attached to anti-VEGF antibodies via carbodiimide chemistry. ...
Colloidal gold is a sol or colloidal suspension of nanoparticles of gold in a fluid, usually water. The liquid is usually either an intense red colour (for particles less than 100 nm) or blue/purple (for larger particles). Due to their optical, electronic, and molecular-recognition properties, gold nanoparticles are the subject of substantial research, with many potential or promised applications. and materials science. The properties of colloidal gold nanoparticles, and thus their applications, depend strongly upon their size and shape. For example, rodlike particles have both transverse and longitudinal absorption peak, and anisotropy of the shape affects their self-assembly. Used since ancient times, the synthesis of colloidal gold was crucial to the 4th-century Lycurgus Cup, which changes color depending on the location of light source. Later it was used as a method of staining glass. During the Middle Ages, soluble gold, a solution containing gold salt, had a reputation for its curative ...
A sensing system has been obtained by self-assembly of multiple fluorescent indicators and monolayer protected gold nanoparticles. The system is able to discriminate between each of the eight nucleotides NDP and NTP (N = A, T, G, C) in a quantitative manner at micromolar concentrations.
We have numerically investigated the influence of a nanoscale silicon tip in proximity to an illuminated gold nanoparticle. We describe how the position of the high-permittivity tip and the size of the nanoparticle impact the absorption, peak electric field and surface plasmon resonance wavelength under different illumination conditions. We detail the finite element method (FEM) approach we have used, whereby we specify a volume excitation field analytically and calculate the difference between this source field and the total field (i.e., scattered-field formulation). We show that a nanoscale tip can locally enhance the absorption of the particle as well as the peak electric field at length scales far smaller than the wavelength of the incident light.. ©2011 Optical Society of America. Full Article , PDF Article ...
Polyvalent DNA gold nanoparticles are colloidal gold whose surface is modified with thiol capped synthetic DNA sequences. They were co-discovered by Chad Mirkin et al. at Northwestern University in 1996 and Paul Alivisatos at University of California, Berkeley. Due to the strong interaction between gold and thiols (-SH), a single monolayer of DNA around the gold particle can be obtained. The negative charge repulsion of the phosphate backbone of DNA orients the DNA strands out into solution with a unique footprint that is dependent on gold nanoparticle size and packing density. (Schematic Image) Simply by positioning many strands into close proximity, these particles possess novel properties in which the independent DNA strands do not. Due to the cooperative effects of the polyvalency of multiple DNA strands, DNA on a particle has a stronger and sharper melting temperature when binding to its complement compared to DNA free in solution. Because of this effect and the unique optical properties of ...
Protein encapsulated gold nanoclusters have received much attention due to the possibility of using them as a non-toxic fluorescent probe or marker for biomedical applications, however one major disadvantage currently is their low brightness and quantum yield in comparison to currently used fluorescent markers. A method of increasing the fluorescence emission of Human Serum Albumin (HSA) encapsulated gold nanoclusters (AuNCs) via a Polyallylamide hydrochloride (PAH) coating is described. PAH molecules with a molecular weight of ~17,500 Da were found to enhance the fluorescence emission of HSA-AuNCs by 3-fold when the protein/polymer concentration ratio is 2:1 in solution. Interestingly, the fluorescence lifetime of the AuNCs was found to decrease while the native tryptophan (TRP) fluorescence lifetime also decreased during the fluorescence emission intensity enhancement caused by the PAH binding. Coinciding with the decrease in fluorescence lifetime, the zeta potential of the system was observed ...
... A gold colloid suspensions containing different size nanoparticles, will be dumped in succesion, and the particles will self assemble into proper sized trenches.
Atomically precise gold nanoclusters are ideal model catalysts with well-defined compositions and tunable structures. Determination of the ligand effect on catalysis requires the use of gold nanoclusters with protecting ligands as the only variable. Two isostructural Au38 nanoclusters, [Au38(L)20(Ph3P)4]2+ (L = alkynyl or thiolate), have been synthesized by a direct reduction method, and they have an unprecedented face-centered cubic (fcc)-type Au34 kernel surrounded by 4 AuL2 staple motifs, 4 Ph3P, and 12 bridging L ligands. The Au34 kernel can be derived from the fusion of two fcc-type Au20 via sharing a Au6 face. Catalytic performance was studied with these two nanoclusters supported on TiO2 (1/TiO2 and 2/TiO2) as catalysts. The alkynyl-protected Au38 are very active (,97%) in the semihydrogenation of alkynes (including terminal and internal ones) to alkenes, whereas the thiolated Au38 showed a very low conversion (,2%). This fact suggests that the protecting ligands play an important role in ...
TY - JOUR. T1 - Protein-assisted 2D assembly of gold nanoparticles on a polysaccharide surface. AU - Taajamaa, Laura. AU - Rojas, Orlando J.. AU - Laine, Janne. AU - Yliniemi, Kirsi. AU - Kontturi, Eero. PY - 2013/1/2. Y1 - 2013/1/2. KW - Nanoparticles; Specific Adsorption; Cationic and anionic surfaces. KW - Nanoparticles; Specific Adsorption; Cationic and anionic surfaces. KW - Nanoparticles. KW - Specific Adsorption. KW - Cationic and anionic surfaces. UR - http://pubs.rsc.org/en/Content/ArticleLanding/2013/CC/c2cc37288f. U2 - 10.1039/c2cc37288f. DO - 10.1039/c2cc37288f. M3 - Article. VL - 49. SP - 1318. EP - 1320. JO - Chemical Communications. JF - Chemical Communications. SN - 1359-7345. IS - 13. ER - ...
Amine gold nanoparticles are available with a 5000Da PEG surface spacers. Our amine gold nanoparticles are available in 12 different sizes ranging from 5-100nm, are more than 95% spherical, and have uniform size distribution (CV,12).. Technical Specifications , Peer Reviewed Publications. ...
Read Gold Nanoparticles in Biomedical Applications by Lev Dykman with Rakuten Kobo. This book discusses fabrication of functionalized gold nanoparticles (GNPs) and multifunctional nanocomposites, their op...
Targeted metallic nanoparticles have shown potential as a platform for development of molecular-specific contrast agents. Aptamers have recently been demonstrated as ideal candidates for molecular targeting applications. In this study, we investigated the development of aptamer-based gold nanoparticles as contrast agents, using aptamers as targeting agents and gold nanoparticles as imaging agents. We devised a novel conjugation approach using an extended aptamer design where the extension is complementary to an oligonucleotide sequence attached to the surface of the gold nanoparticles. The chemical and optical properties of the aptamer−gold conjugates were characterized using size measurements and oligonucleotide quantitation assays. We demonstrate this conjugation approach to create a contrast agent designed for detection of prostate-specific membrane antigen (PSMA), obtaining reflectance images of PSMA(+) and PSMA(−) cell lines treated with the anti-PSMA aptamer−gold conjugates. This ...
We demonstrate a phase transfer method to create stable colloidal solutions of Au nanoparticles with 4-methoxypyridine ligands. We then investigate the adsorption behavior of 4-methoxypyridine onto gold surfaces by Raman spectroscopy, DFT calculations, and 1H NMR. In contrast to unsubstituted pyridine and the frequently used (N,N-dimethylamino)pyridine (DMAP), a flat adsorption of 4-methoxypyridine on gold was found. ...
The objective of the present investigation was to evaluate the effects of taurine and Au nanoparticles on the expression of genes related to embryonic muscle development and on the morphological characteristics of muscles. Fertilised chicken eggs (n = 160) were randomly divided into four groups: without injection (Control) and with injection of Au nanoparticles (NanoAu), taurine (Tau) or Au nanoparticles with taurine (NanoAu + Tau). The experimental solutions were given in ovo, on the third day of incubation, by injecting 0.3 ml of the experimental solution into the air sack. The embryos were evaluated on the 20th day of incubation. The methods included gene expression at the mRNA and protein levels, immunohistochemistry, histology and microscopy. In groups NanoAu, Tau and NanoAu + Tau, the muscle structure and the number of muscle cells were affected. Furthermore, taurine increased fibre diameter, the total number of nuclei, the proportion of proliferating cell nuclear antigen (PCNA)-positive ...
TY - JOUR. T1 - Spectroscopic ellipsometry of yttrium-iron garnet thin films containing gold nanoparticles. AU - Tomita, Satoshi. AU - Fujii, Minoru. AU - Hayashi, Shinji. AU - Terai, Asuka. AU - Nabatova-Gabain, Nataliya. PY - 2007/11/9. Y1 - 2007/11/9. N2 - We report complex dielectric function (ε) for yttrium-iron garnet thin films containing Au nanoparticles. Films are prepared using a co-sputtering method with post-annealing. Real and imaginary parts of e of the films are obtained using spectroscopic ellipsometry in a photon energy region from near-infrared to ultra-violet. An anomalous dispersion of Re[ε] in the visible region originating from localized surface plasmon of Au nanoparticles is clearly observed. The influence of e on the magnetooptical Kerr properties of the nanocomposite films is discussed.. AB - We report complex dielectric function (ε) for yttrium-iron garnet thin films containing Au nanoparticles. Films are prepared using a co-sputtering method with post-annealing. ...
Two different methods were used to obtain polypyrrole/AuNP (Ppy/AuNP) composites. One through the electrooxidation of the pyrrole monomer in the presence of colloidal gold nanoparticles, referred to as trapping method (T), and the second one by electrodeposition of both components from one solution containing the monomer and a gold salt, referred to as cogeneration method (C). In both cases, electrodeposition was carried out through galvanostatic and potentiostatic methods and using platinum (Pt) or stainless steel (SS) as substrates. Scanning electron microscopy (SEM) demonstrated that in all cases gold nanoparticles of similar size were uniformly dispersed in the Ppy matrix. The amount of AuNPs incorporated in the Ppy films was higher when electropolymerization was carried out by chronopotentiometry (CP). Besides, cogeneration method allowed for the incorporation of a higher number of AuNPs than trapping. Impedance experiments demonstrated that the insertion of AuNPs increased the ...
Gold nanostars are theoretically studied as efficient thermal heaters at their corresponding localized surface-plasmon resonances (LSPRs). Numerical calculations are performed through the 3D Greens Theorem method to obtain the absorption and scattering cross sections for Au nanoparticles with star-like shape of varying symmetry and tip number. Their unique thermoplasmonic properties, with regard to their (red-shifted) LSPR wavelentgh, (∼ 30-fold increase) steady-state temperature, and scattering/absorption cross section ratios, make them specially suitable for optical heating and in turn for cancer thermal therapy.. © 2011 Optical Society of America. Full Article , PDF Article ...
TY - JOUR. T1 - The influence of flow, shear stress and adhesion molecule targeting on gold nanoparticle uptake in human endothelial cells. AU - Klingberg, Henrik. AU - Loft, Steffen. AU - Oddershede, Lene B.. AU - Moller, Peter. PY - 2015/2/1. Y1 - 2015/2/1. U2 - 10.1039/c5nr01467k. DO - 10.1039/c5nr01467k. M3 - Journal article. VL - 7. SP - 11409. EP - 11419. JO - Nanoscale. JF - Nanoscale. SN - 2040-3364. IS - 26. ER - ...
TY - JOUR. T1 - The fabrication of low-impedance nanoporous gold multiple-electrode arrays for neural electrophysiology studies. AU - Seker, Erkin. AU - Berdichevsky, Yevgeny. AU - Begley, Matthew R.. AU - Reed, Michael L.. AU - Staley, Kevin J.. AU - Yarmush, Martin L.. PY - 2010/3/19. Y1 - 2010/3/19. N2 - Neural electrodes are essential tools for the study of the nervous system and related diseases. Low electrode impedance is a figure of merit for sensitive detection of neural electrical activity and numerous studies have aimed to reduce impedance. Unfortunately, most of these efforts have been tethered by a combination of poor functional coating adhesion, complicated fabrication techniques, and poor fabrication repeatability. We address these issues with a facile method for reliably producing multiple-electrode arrays with low impedance by patterning highly adherent nanoporous gold films using conventional microfabrication techniques. The high surface area-to-volume ratio of self-assembled ...
We report on the electronic structure of Au (gold) nanoparticles supported onto TiO 2 with a goal of elucidating the most important effects that contribute to their high catalytic activity. We synthesize and characterize with high resolution transmission electron microscopy (HRTEM) 3.4, 5.3, and 9.5 nm diameter TiO 2-supported Au nanoparticles with nearly spherical shape and measure their valence band using Au 5d subshell sensitive hard X-ray photoelectron spectroscopy (HAXPES) conducted at Spring-8. Based on density functional theory (DFT) calculations of various Au surface structures, we interpret the observed changes in the Au 5d valence band structure as a function of size in terms of an increasing percentage of Au atoms at corners/edges for decreasing particle size. Finally, this work elucidates how Au coordination number impacts the electronic structure of Au nanoparticles, ultimately giving rise to their well-known catalytic activity. ...
Wegener, Joachim, Sieber, M. und Galla, H.-J. (1996) Impedance analysis of epithelial and endothelial cell monolayers cultured on gold surfaces. Journal of biochemical and biophysical methods . J. Biochem. Biophys. Methods 32, S. 151-170 ...
Gold nanoparticles prepared by laser ablation in aqueous biocompatible solutions: assessment of safety and biological identity for nanomedicine applications Abstract: Due to excellent biocompatibility, chemical stability, and promising optical properties , gold nanoparticles (Au-NPs) are the focus of research and applications in nanomedicine. Au-NPs prepared by laser ablation in aqueous biocompatible solutions present an essentially novel object that is unique in avoiding any residual toxic contaminant. This paper is conceived as the next step in development of laser-ablated Au-NPs for future in vivo applications. The aim of the study was to assess the safety, uptake, and biological behavior of laser-synthesized Au-NPs prepared in water or polymer solutions in human cell lines. Our results showed that laser ablation allows the obtaining of stable and monodisperse Au-NPs in water, polyethylene glycol, and dextran solutions. The three types of Au-NPs were internalized in human cell lines, as shown ...
Delivery of vincristine sulfate-conjugated gold nanoparticles using liposomes: a light-responsive nanocarrier with enhanced antitumor efficiency Ying Liu,1,* Man He,1,* Mengmeng Niu,1 Yiqing Zhao,1 Yuanzhang Zhu,1 Zhenhua Li,2 Nianping Feng1 1Department of Pharmaceutical Sciences, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 2Cedars-Sinai Medical Center, Los Angeles, CA, USA *These authors contributed equally to this work Abstract: Rapid drug release at the specific site of action is still a challenge for antitumor therapy. Development of stimuli-responsive hybrid nanocarriers provides a promising strategy to enhance therapeutic effects by combining the unique features of each component. The present study explored the use of drug–gold nanoparticle conjugates incorporated into liposomes to enhance antitumor efficiency. A model drug, vincristine sulfate, was physically conjugated with gold nanoparticles and verified by
Alfa Aesar™ Gold nanoparticles, 400nm, supplied in 0.1mg/mL sodium citrate with stabilizer 25mL Alfa Aesar™ Gold nanoparticles, 400nm, supplied...
Alfa Aesar™ Gold nanoparticles, 250nm, supplied in 0.1mg/mL sodium citrate with stabilizer 100mL Alfa Aesar™ Gold nanoparticles, 250nm, supplied...
Two decades ago, it was found that gold is catalytically active as clusters although it is known to be inert as bulk material. In the work presented in this thesis, density functional theory calculations have been applied to show that the properties of gold clusters and small molecules, namely O2 and NO2, are di erent on oxide thin lms supported by metal carriers than on single crystal oxide surfaces. Collectively, these di erences are called thin- lm e ects. The e ects and the mechanisms behind them have been studied with atomistic calculations and rationalized with simple physical models. The signi cance of the thin- lm e ects for heterogeneous catalysis is discussed. It has been found that on MgO/Mo thin lm, the adsorption of gold clusters is strong, whereas on single crystal MgO, the adsorption is weak. On MgO/Mo and MgO/Ag, the clusters are charged and tend to maximize their surface contact whereas on single crystal MgO, they are essentially neutral and the smallest clusters have only few ...
Gold nanoparticles, Nanogold conjugates & labeling reagents for immunolabeling, EM, correlative and fluorescence microscopy, enzyme metallography & x-ray contrast agents for micro-CT.
TY - JOUR. T1 - EGCG/gelatin-doxorubicin gold nanoparticles enhance therapeutic efficacy of doxorubicin for prostate cancer treatment. AU - Tsai, Li Chu. AU - Hsieh, Hao Ying. AU - Lu, Kun Ying. AU - Wang, Sin Yu. AU - Mi, Fwu Long. PY - 2016/1/1. Y1 - 2016/1/1. N2 - Aim: Development of epigallocatechin gallate (EGCG) and gelatin-doxorubicin conjugate (GLT-DOX)-coated gold nanoparticles (DOX-GLT/EGCG AuNPs) for fluorescence imaging and inhibition of prostate cancer cell growth. Materials & methods: AuNPs alternatively coated with EGCG and DOX-GLT conjugates were prepared by a layer-by-layer assembly method. The physicochemical properties of the AuNPs and the effect of Laminin 67R receptor-mediated endocytosis on the anticancer efficacy of the AuNPs were examined. Results: The AuNPs significantly inhibit the proliferation of PC-3 cancer cell and the enzyme-responsive intracellular release of DOX could be tracked by monitoring the recovery of the fluorescence signal of DOX. Conclusion: Laminin 67R ...
Government intervention against the price of gold is not mere "conspiracy theory" but an old story fully documented in governments own archives. It is official policy going back to the United States governments enactment of the Gold Reserve Act of 1934, which created the U.S. governments Exchange Stabilization Fund. This policy of gold price suppression continued through the London Gold Pool of the 1960s, a coordinated scheme of gold reserve dishoarding by the U.S. government and seven allied governments to hold the international gold price at $35 per ounce. The objective of these interventions always has been to defend government currencies and bonds against competition from gold as a currency and store of value. But by the early 1970s the governments participating in gold price suppression had lost too much of their gold reserves to continue suppressing the gold price by dishoarding in the open. So they began operating against gold mostly in secret, through gold leasing, swapping, and ...
Nanoparticle gold is a suspension of sub-micron gold particles typically dispersed in water. Gold nanoparticles are of great interest for researchers in many fields due to their unique physical and optical properties. These properties change with the particle size distribution, so size analysis is an important measurement requirement.
Also known as colloidal gold, gold nanoparticles are small gold crystals that can range in size from a few nanometers (10-9 meters) to several hundred n...
Although gold nanoparticle production can be controlled to yield specific size ranges, both the concentration and size of nanoparticles must be checked
Page contains details about citrate-stabilized gold nanoparticle-integrated citrate-stabilized gold nanoparticle attached tin dioxide nanofiber . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
TY - JOUR. T1 - Effect of substrates on the melting temperature of gold nanoparticles. AU - Lee, Joonho. AU - Tanaka, Toshihiro. AU - Lee, Junggoo. AU - Mori, Hirotaro. PY - 2007/3. Y1 - 2007/3. N2 - The size-dependent melting temperature of metallic nanoparticles (NPs) is generally examined on a solid substrate. However, most experimental works performed on a solid substrate were explained by a homogeneous particle model without considering the effect of the substrate. For example, in the previous studies, the melting temperatures of gold NPs were examined on carbon or tungsten substrates. However, the experimental results were described only by the surface tension of gold, without interfacial tension between gold and substrate. In the present work, the effect of the sorts of substrate on the melting temperatures of gold NPs was examined by using a thermodynamic model equilibrating the chemical potentials of liquid and solid particles. For this study, graphite, alumina and tungsten substrates ...