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Search for "gold Nanoparticles" in Full Text gives 239 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
The eNanoMapper database for nanomaterial safety information
Beilstein J. Nanotechnol. 2015, 6, 1609–1634, doi:10.3762/bjnano.6.165
- association of a 105-member library of surface-modified gold nanoparticles (see Figure 3). 785 distinct serum proteins were identified by LC-MS/MS, from which 129 were suitable for relative quantification. The fingerprint of serum proteins was defined by the relative abundance of each protein on a
Scalable, high performance, enzymatic cathodes based on nanoimprint lithography
Beilstein J. Nanotechnol. 2015, 6, 1377–1384, doi:10.3762/bjnano.6.142
- found to be equal to 27 s−1. It appears that the heterogeneous electron transfer rate for the adsorbed BOx does not depend on electrode nanostructuring. These results are in excellent agreement with our previously published data concerning the influence of gold nanoparticles on enzymatic bio
Formation of substrate-based gold nanocage chains through dealloying with nitric acid
Beilstein J. Nanotechnol. 2015, 6, 1362–1368, doi:10.3762/bjnano.6.140
- . 16%) [31]. A slow reaction could avoid the removal of the nanocages from the solid substrate. The gaseous product of the reaction may be the force to move the nanoparticles and the affinity between the gold nanoparticles may be the driving force of the chain formation. However, the details of the
Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles
Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124
- Simon Ristig Svitlana Chernousova Wolfgang Meyer-Zaika Matthias Epple Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45117 Essen, Germany 10.3762/bjnano.6.124 Abstract Alloyed silver–gold nanoparticles were prepared in nine different
- ) showed spherical, monodisperse, colloidally stable silver–gold nanoparticles of ≈7 nm diameter with measured molar metal compositions very close to the theoretical values. The examination of the nanoparticle cytotoxicity towards HeLa cells and human mesenchymal stem cells (hMSCs) showed that the toxicity
- scientific studies due to their distinct physicochemical properties [1][2]. Apart from their catalytic and optical features, in particular, silver and gold nanoparticles have begun to play a major role in biochemistry, biology and medicine [3][4][5]. Silver nanoparticles are known to be highly toxic towards
Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement
Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122
- was believed to be due to nonlinear scattering. Polavarapu et al. [21] have shown that nonlinear absorption was not significant for the gold nanoparticles in water. At low laser fluence, the nanoparticle dispersion is almost transparent to the laser light and thus the laser light exhibits a linear
- threshold is about 1.6 J/cm2. Hence, by adding the silica microspheres, the optical limiting threshold is lowered by 4.6 J/cm2. Figure 3b shows the normalized nonlinear transmittance of the samples (gold nanoparticles and gold/silica nanocomposites) upon excitation with ns laser pulses at 1064 nm. The input
- nanoparticle dispersion is almost transparent upon illumination by laser light at low laser fluence. (b) The optical limiting effect of the nanoparticles appears when microbubbles are formed at high laser fluence. Optical limiting (OL) response and normalized transmittance curves of (a,b) gold nanoparticles
Patterning technique for gold nanoparticles on substrates using a focused electron beam
Beilstein J. Nanotechnol. 2015, 6, 1010–1015, doi:10.3762/bjnano.6.104
- , Midori-ku, Yokohama, 226-8502, Japan 10.3762/bjnano.6.104 Abstract We propose a novel patterning technique for gold nanoparticles on substrates that combines a chemical reaction with electron beam irradiation. First, gold nanoparticles are placed in a two-dimensional arrangement on the substrate. Then
- , particular nanoparticles are fixed on the substrate by irradiation with a focused electron beam to produce a desired pattern. Finally, the unfixed nanoparticles are removed. Using this technique, an array of gold nanoparticles, for example, in the form of a line or patterned over an area, are prepared on the
- substrate. This technique could contribute to the fabrication of plasmonic devices and other applications that require the controlled placement of gold nanoparticles on substrates. Keywords: electron beam; gold; nanoparticle array; Introduction Plasmonic waveguides and circuits utilizing localized surface
Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development
Beilstein J. Nanotechnol. 2015, 6, 651–664, doi:10.3762/bjnano.6.66
- fertility parameters deteriorated after co-incubation with ligand free gold nanoparticles. However, the effect could be alleviated by bio-coating the nanoparticles, which even applies to silver and silver-rich alloy nanoparticles. The most sensitive test system appeared to be in vitro oocyte maturation
- nanoparticles. In a multigenerational study using gold nanoparticles in an caenorhabditis elegans model it was recently shown that after oral nanoparticle exposure reproduction rate was clearly affected in the F2 generation [1]. While many reprotoxicological examinations are performed as clinical or animal
- evolved sufficiently to allow for the mass production of engineered nanoparticles. Due to their fascinating optical, chemical and physical properties they quickly found their way into many products. With regard to gold nanoparticles this applies particularly to biomedical purposes such as cancer imaging
Filling of carbon nanotubes and nanofibres
Beilstein J. Nanotechnol. 2015, 6, 508–516, doi:10.3762/bjnano.6.53
- [71]. MWCNT samples decorated with gold nanoparticles on the interior and exterior surfaces were produced by first functionalizing the CNTs with carboxylic acid groups [65]. This was followed by sonication of the functionalized MWCNTs in water and application of a large (225 V) potential across two
- ) Transmission electron micrograph of the filled CNFs with gold nanoparticles. Inset: a computer generated model. Reprinted with permission from [30], copyright 2012 Wiley-VCH.
Raman spectroscopy as a tool to investigate the structure and electronic properties of carbon-atom wires
Beilstein J. Nanotechnol. 2015, 6, 480–491, doi:10.3762/bjnano.6.49
- spectrum. A shift in the main Raman peak locations is accompanied by the appearance of new spectral features at lower wavenumbers (below 2000 cm−1), as shown in Figure 6 for the case of silver nanoparticles. This occurs also in the case of gold nanoparticles for different excitation wavelengths ranging
Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization
Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28
- nanoparticles on endothelial cells. Our findings will help to design new nanoparticles with optimized properties concerning biocompatibility and uptake behavior with respect to the respective intended application. Keywords: cell viability; gold nanoparticles; internalization; Janus particles; quantum dots
- positive). Gold nanoparticles exhibit strong light scattering and absorption at their resonance wavelength due to their plasmonic properties [1][2]. Thus, these particles are used for optical imaging approaches [3][4]. Moreover, applications as contrast media for CT [5][6] and for selective cell targeting
- [7] are suggested. Gold nanorods were shown to have better optical imaging properties compared to spherical gold nanoparticles [8][9][10]. Importantly, the cytotoxicity of gold nanoparticles depends on the surface coating. Cetyltrimethylammonium bromide (CTAB), an important material during synthesis
Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents
Beilstein J. Nanotechnol. 2015, 6, 293–299, doi:10.3762/bjnano.6.27
- capability to reduce silver and gold salts and to create silver and gold nanoparticles. We report the preparation of silver nanoparticles with sizes between 10 and 300 nm from silver nitrate using fruit extract collected from pineapples and oranges as reducing agents. The evolvement of a characteristic
- process. The most popular process among the bottom up methods might be the preparation of silver and gold nanoparticles in aqueous solution by the reduction of silver and gold salts using sodium citrate or sodium borohydride as reducing agent [9]. Recently it has been identified that also plant extracts
- have the capability to reduce silver and gold salts and to create silver and gold nanoparticles [10][11][12][13][14][15][16][17][18][19]. Many different chemical compounds are present in various parts of different plants. Polysaccharides, phenolics, flavoids to mention only a few, could serve as
Mechanical properties of MDCK II cells exposed to gold nanorods
Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21
- /bjnano.6.21 Abstract Background: The impact of gold nanoparticles on cell viability has been extensively studied in the past. Size, shape and surface functionalization including opsonization of gold particles ranging from a few nanometers to hundreds of nanometers are among the most crucial parameters
- CTAB coated rods suggesting an increase in acoustic load corresponding to a larger stiffness (storage modulus). Keywords: atomic force microscopy; CTAB; gold nanorods; membrane tension; MDCK II cells; QCM; Introduction The interest in gold nanoparticles (NP) for biomedical applications in the field
- simultaneously the resonance frequency and dissipated energy of the quartz crystal covered with cells and reveals information about the viscoelastic properties of these cells as well as the distance from the quartz surface [24]. In the work presented here we investigated the influence of gold nanoparticles on
Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells
Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16
- was chosen as a model cell line. Hela cells are a well-established malignant cell line, which was widely used to study the uptake of iron oxide nanoparticles [18][21][24][32], gold nanoparticles [33][34] and other particle systems like quantum dots [35] or polymer particles [36][37]. To gain insights
- of nanoparticles by HeLa cells is consistent with the literature. It was shown, that polyethyleneimine gold nanoparticles around 40 nm [33], gold nanoparticles of 4.5 nm [34] and conjugated polymer nanoparticles [36] are internalized through Caveolin dependent pathways. The same was observed for
- human alveolar epithelial cells and polystyrene nanoparticles around 100 nm [38] as well as polymer coated gold nanoparticles with a core size around 13 nm [39]. On the other hand there are studies showing the uptake of different nanoparticles by HeLa cells such as quantum dots [35], PEG-PLA particles
Functionalization of α-synuclein fibrils
Beilstein J. Nanotechnol. 2015, 6, 124–133, doi:10.3762/bjnano.6.12
- -synuclein that contains an additional cysteine residue. The fibrils have been biotinylated via thiol groups and subsequently joined with neutravidin-conjugated gold nanoparticles. Atomic force microscopy and transmission electron microscopy confirmed the expected structure – nanoladders. The ability of
- fibrils (and of the additional components) to assemble into such complex structures offers new opportunities for fabricating novel hybrid materials or devices. Keywords: α-synuclein; atomic force microscopy; gold nanoparticles; nanostructures; self-assembly; Introduction Due to their ability to form
- modification of the target protein. Novel well-ordered multicomponent nanoderivatives have been constructed by labelling α-SynC141 fibrils with biotin. The biotinylated fibrils have been further assembled with neutravidin-conjugated gold nanoparticles. The resulting structures were evaluated by AFM and TEM
Bright photoluminescence from ordered arrays of SiGe nanowires grown on Si(111)
Beilstein J. Nanotechnol. 2014, 5, 2498–2504, doi:10.3762/bjnano.5.259
- positioned [28]. We have evolved an efficient and simple electrochemical process that joins focused-ion-beam (FIB) lithography and galvanic reaction to selectively prepare gold nanoparticles in well-defined locations. Afterwards these nanoparticles are used for the molecular beam epitaxy (MBE) growth of
Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating
Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257
- ; gold; nanoparticles; Introduction Over the last decade, the biomedical applications for gold nanoparticles have become increasingly diverse due to their small size and plasmonic nature [1]. The plasmon resonance wavelength of the nanoparticle, which exhibits strong light scattering and absorption, can
- be controlled by synthesis conditions [2] in order to match the “optical window” of biological tissue in the wavelength region of 650–900 nm [3]. Therefore, gold nanoparticles can be used, for example, as biosensors [4][5], as delivery systems [6][7], as contrast agents in imaging [8][9], and as
- special functionality), this study is focused on the impact of basolateral exposure of gold nanoparticles on epithelial cells. Here, epithelial cells were exposed to nanoparticles adsorbed onto a surface. Since MDCK II cells exhibit caveolae only basolaterally, it is conceivable that internalization is
Interaction of dermatologically relevant nanoparticles with skin cells and skin
Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245
- in vivo over time [12]. On the other hand, hair follicles were found to be excretion pathways for injected gold nanoparticles [15]. Raman microscopy is another technique with high spatial resolution which permits such studies. While we gathered first own results on skin with the in vivo detection of
Inorganic Janus particles for biomedical applications
Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244
- the control over the size was much more precise performing a synthesis of hydrophobic gold nanoparticles using tert-butylamine borane complex as reducing agent [74]. The size of the oleylamine-capped particles is varied between 2 and 8 nm by changing the reaction temperature or in a subsequent growth
- ], the gold nanoparticles were functionalized with 1-octadecanethiol to suppress multiple nucleation of manganese oxide on different crystal facets or surface defects. This surface functionalization was proved not to be necessary for Au@Fe3O4 heterodimers. The morphology as well as the sizes of the metal
- . attributed this broadening and damping to the tunnelling of conduction band electrons of the Au nanoparticles into the projected density of states of the Fe3O4 domains, the so-called “interface decay channel” [56]. As a metal oxide starts to nucleate heterogeneously on the gold nanoparticles, the induced
Liquid-phase exfoliated graphene: functionalization, characterization, and applications
Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242
- to pure DMF. In this process, carbon nanofibers (CNFs) are formed revealing the occurrence of chemical reactions. During the ultrasonication process, graphene sheets were cut close to the edges, producing small fragments which later aggregate into CNFs. To verify the mechanism of CNF formation, gold
- nanoparticles (Au NPs) were introduced as contrast markers. Tiopronin and its fragments are well-known stabilizers for Au NPs. The analysis by transmission electron microscopy (TEM) showed Au NPs mostly resided on the nanofibers, thus supporting the proposed mechanism as shown in Figure 2. This methodology
Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity
Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237
- observed and correspond to the nonlinear wave mixing: SFG, SHG (second harmonic generation) and CARS signals. Interestingly, coupling nano-objects, i.e., tuning the distance between gold nanoparticles until they get in contact [60], shifts the frequency of the LSPR. For an optimal distance, i.e., when LSPR
- signature of thiophenol-functionalized gold nanoparticles (17 nm of diameter) grafted on flat silicon could be detected at a surface coverage as low as about 1% [70][71]. The SFG spectra displayed a single mode corresponding to the CH groups of the aromatic core of thiophenol at 3055 cm−1 (Figure 6). The Au
- was studied by Tourillon et al. [74], for which the SFG spectroscopy was performed on a dense gold nanoparticles monolayer (11 nm) on a quartz prism surface. The interface was probed in the total internal reflection (TIR) configuration, in ppp polarization, with the visible frequency matching the LSPR
Influence of stabilising agents and pH on the size of SnO2 nanoparticles
Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228
- stabilising agents significantly affect the size, shape and surface properties of nanomaterials synthesised in their presence [18]. In 1718, Helcher applied a natural polymer (starch) to stabilise gold nanoparticles [19]. Today, synthetic polymers are commonly used to stabilise different types of
Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films
Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219
- theory with the temperature gradients both lateral and normal to the film surface taken into account [8][9][10]. The gold nanoparticles produced from thin Au films on Si and indium tin oxide (ITO) substrates using a 532 nm laser operated in a single-pulse regime were studied in detail by Ruffino et al
Effect of silver nanoparticles on human mesenchymal stem cell differentiation
Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214
- within the endo-lysosomes after 24 h. Fröhlich et al. [36] have reported that access to other organelles depends on the particle size. Similarly, as suggested by Berry et al., the uptake of nanoparticles is constrained by the dimensions of the nuclear pore because gold nanoparticles (Au-NP) with a size
- was impaired at subtoxic concentrations of Ag-NP and Ag+ ions, whereas chondrogenic differentiation was not influenced by the presence of silver. Similar results were observed by Fan et al. when using gold nanoparticles [46]. These nanoparticles, with a size of 30 nm, led to decreases in the
PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments
Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205
- ]. Specifically, we have addressed the effect of a PVP coating around the metallic surface of silver and, for comparison, gold nanoparticles, on the adsorption/desorption equilibrium of serum albumin molecules – an established model protein [57][59][60][61][62]. To quantify this equilibrium, we have used circular
- containing PVP-coated silver nanoparticles at various concentrations as well as the corresponding analytical plot. Equilibrium constants for the adsorption of albumin to silver and gold nanoparticles with and without a PVP coating were determined, revealing the influence of the polymer coating on the ability
- localization of silver in the perinuclear region was observed (Figure 5A). In none of the investigated cells an indication for uptake into the nucleus was found, which is in agreement with a quantitative TEM analysis of citrate- or polyethylene glycol (PEG)-stabilized gold nanoparticles, in which no particles
Towards bottom-up nanopatterning of Prussian blue analogues
Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204
- deposition, whatever the deposition time, the silicon substrate is completely and homogeneously covered by gold nanoparticles (as expected for sputtering deposition). But, the size of the particles depends on the deposition time. The gold layers obtained with 30 s, 60 s and 150 s deposition time are composed
- of gold nanoparticles of 10 nm, 15 nm and 40 nm in diameter, respectively. The roughness is 0.27 nm for the silicon substrate, 0.44 nm for the 10 nm thick gold layer, 0.48 nm for the 20 nm thick gold layer and 1.01 nm for the 50 nm thick one. After the gold deposition, the surfaces exhibit a small
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