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Search for "gold nanoparticle" in Full Text gives 63 result(s) in Beilstein Journal of Nanotechnology.
The role of ligands in coinage-metal nanoparticles for electronics
Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263
- irregular shapes (coin-like or rounded nanoplates) [71]. Wang et al. modified gold nanoparticle seeds (20 nm in diameter) with different bifunctional ligands and used them to initiate gold shell growth in a solution of HAuCl4, cetyltrimethylammonium chloride, and ascorbic acid. The morphologies of the
- by gold nanoparticles to create interconnected gold-nanoparticle assemblies with a homogeneous coverage and a film conductivity of 4.2 × 10−3 S/cm [118]. Cross-linking works for particles that are not prepared in liquids, too. A discontinuous film of gold was evaporated onto a mica substrate and
Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass
Beilstein J. Nanotechnol. 2017, 8, 2454–2463, doi:10.3762/bjnano.8.244
- ). The samples were then annealed at 600 °C for 30 min. Dependence of the position of the plasmon resonance extinction band maximum on the gold nanoparticle diameter obtained from Equation 1. Optical microscope image of a structure fabricated 1.5 mm below the surface of a gold-doped glass sample by
Fixation mechanisms of nanoparticles on substrates by electron beam irradiation
Beilstein J. Nanotechnol. 2017, 8, 1523–1529, doi:10.3762/bjnano.8.153
- nanoparticles and the width of the fixing areas in the technique, proposed by T. Noriki et al. [8], to fabricate gold nanoparticle arrays on substrates are studied by means of both experiments and simulation. The widths are measured and calculated with changing the accelerating voltage, particle size and
- ) the scan of electron beam, and (iii) the removal of unfixed particles. Schematic illustration of the calculation of electron trajectories using Monte Carlo modeling: (1) electrons incident to a gold nanoparticle; (2) electrons incident to the Si substrate. Acknowledgements This work was partly
Comparison of four functionalization methods of gold nanoparticles for enhancing the enzyme-linked immunosorbent assay (ELISA)
Beilstein J. Nanotechnol. 2017, 8, 244–253, doi:10.3762/bjnano.8.27
- approach, our data showed a sensitivity increase of at least five times and a lower detection limit with respect to a standard ELISA of at least three times. Additionally, the assay time was remarkably decreased. Keywords: allergen; ELISA enhancement; functionalization; gliadin; gold nanoparticle
- combining primary antibodies with HRP, avoiding tedious chemical labelling procedures. Experimental 20 nm gold nanoparticle synthesis All glassware was cleaned with aqua regia (HNO3/HCl, 3:1), rinsed with deionized water and let dry before use. 20 µL of 30% HAuCl4·3H2O was added to 95 mL of deionized water
- spectrophotometer (Supporting Information File 1, Figure S1). Gold nanoparticle functionalization Four different strategies were assayed in this work and are schematized in Figure 1. For the direct adsorption functionalization, 133 μL of 15 mM borate buffer pH 8.7 were added to 1 mL of AuNPs synthetized as
Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate
Beilstein J. Nanotechnol. 2017, 8, 237–243, doi:10.3762/bjnano.8.26
- intensities of 9% is calculated [30]. SERS monitoring of MG adsorbed on gold nanoparticle spots The adsorption and desorption process of MG was studied as well on a SERS active gold substrate. Even though the Raman signal enhancement of gold is lower than silver, this material is often employed in SERS
- and no SERS signal of MG was observed anymore. Conclusion We reported a straightforward approach for on-line preparation of silver and gold nanoparticle spots as SERS active substrates, which was used for fast detection of the model compound MG. By using silver or gold spots as SERS substrate, the
- synthesis of the SERS active spot, MG adsorption to the metal surface, detection of the analyte, and finally the desorption of MG from the spot. Moreover, after MG complete desorption, the regeneration of the SERS active spot was achieved. A main advantage of the she silver and gold nanoparticle spots is
Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation
Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1
- suspension on TEM grids often introduces artifacts [52]. In our case, the formation of aggregates in the liquid dispersion is demonstrated by the plasmon band at 600 nm observed in absorbance spectra of AuNP-SA-BiotinDNA after displacement by free biotin (Figure 4A). A red-shifted contribution to the gold
- nanoparticle plasmon band has been consistently observed from dispersions of AuNPs linear aggregates [53][54][55]. In addition, it has been demonstrated that bands generated by linear aggregates allow to discriminate between linear and spherical aggregates [53]. We confirmed the displacement of BiotinDNA from
Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers
Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196
- .7.196 Abstract Gold nanoparticle monolayers provide convenient templates to study charge transport in organic molecules beyond single junction techniques. Conductance is reported to increase by several orders of magnitude following immersion of alkanethiol-stabilized gold nanoparticle monolayers in a
- solution containing conjugated thiol-functionalized molecules. Typically, this observation is attributed to molecular exchange. Less attention has been paid to the role of the solvent alone. Here, we report on an increase in conductance of dodecanethiol-stabilized gold nanoparticle monolayers on Si/SiO2 by
- networks; Self-assembly; Introduction Ordered gold nanoparticle monolayers are increasingly applied as templates for molecular resistor networks [1][2][3][4][5][6][7][8]. Gold nanoparticles serve as conducting nodes and different molecules can bind to the gold nanoparticle using anchoring groups such as
Effect of Anderson localization on light emission from gold nanoparticle aggregates
Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192
- resonance and in the photoluminescence emission. The geometry of the gold nanoparticle aggregates determine the strength of the Anderson localization, and hence, the light emission from the aggregates. The photoluminescence lifetime was found to be dependent on the AuNP aggregate geometry and the dielectric
- constant of the medium. Keywords: Anderson localization; gold nanoparticle aggregates; photoluminescence; plasmons; surface plasmon resonance; Introduction The process of localization of waves has been observed in several physical phenomena, such as for excitons in semiconductor nanostructures [1] and
Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors
Beilstein J. Nanotechnol. 2016, 7, 1948–1959, doi:10.3762/bjnano.7.186
- : catechol; gold nanoparticle hydroquinone; PEDOT/PSS; phthalocyanine; voltammetric sensor; Introduction The assessment of phenols has been successfully achieved using electrodes chemically modified with a variety of materials [1][2][3][4][5][6][7][8][9][10]. In addition, some mixtures of electrocatalytic
- ) and copper(II) phthalocyanine tetrasulfonic acid tetrasodium salt (CuPc, 0.05 g/L) were purchased from Sigma-Aldrich. Gold nanoparticle (AuNPs, 30–40 nm) colloids were synthesized according to a modification of the procedure proposed by Slot and Geuze [12][40]. Using this procedure, a red colloid with
Photothermal effect of gold nanostar patterns inkjet-printed on coated paper substrates with different permeability
Beilstein J. Nanotechnol. 2016, 7, 1480–1485, doi:10.3762/bjnano.7.140
- output [25][26]. The photothermal properties of printed gold nanoparticle patterns on paper substrates have not been fully explored yet, and this is the main aim of this study. We reported recently that GNS patterns inkjet-printed onto semi-permeable paper display a substantial photothermal effect with
Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures
Beilstein J. Nanotechnol. 2016, 7, 948–956, doi:10.3762/bjnano.7.87
- conventional top-down fabrication methods in nanotechnology. Their positioning onto specific locations of a microstructured substrate is an important task towards this aim. Here we study manipulation and positioning of pristine and of gold nanoparticle-conjugated tubular DNA origami structures using ac
- between electrodes at applied frequencies in the megahertz range was observed. The long-range chain formation is caused by a local, gold nanoparticle-induced field concentration along the DNA nanostructures, which in turn, creates dielectrophoretic forces that enable the observed self-alignment of the
- that the tubular DNA/gold-nanoparticle hybrid structure possesses a different dielectrophoretic response than its unmodified counterpart. Trapping at the electrodes edges was observed at a lower electrical field strength (1·105 V/m) and lower frequencies in the kilohertz range (e.g., 500 kHz with 1·106
The role of morphology and coupling of gold nanoparticles in optical breakdown during picosecond pulse exposures
Beilstein J. Nanotechnol. 2016, 7, 869–880, doi:10.3762/bjnano.7.79
- interactions at the nanoscale using nanoparticles. This relies on the unique tunable optical properties of gold nanoparticle stemming from the interaction of light with the quasi-free electrons in gold. The oscillation of these electrons induces surface plasmon resonance, resulting in the enhancement of the
- surface of cell [6][7][8][9], modification of gold nanoparticle surfaces to cause binding to each other [10][11] or endocytosis [12]. Nanoparticle assemblies exhibit optical behavior that differs from single particles. The changes in the optical behavior of nanoparticle assemblies are governed by surface
- surpasses a certain threshold (which will henceforth be referred to as the “optical breakdown threshold”) and the free-electron density exceeds a critical value in the range of 1018–1021 cm−3 [17][22][23][24][25][26]. The interaction of a strong electromagnetic field with a gold nanoparticle in an aqueous
Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures
Beilstein J. Nanotechnol. 2016, 7, 351–363, doi:10.3762/bjnano.7.32
- Hcp1_cys3 material with decreasing blocking temperature. Results and Discussion Gold nanoparticle assembly The Au NPs used in the following experiments have a mean diameter of 10.7 ± 2.0 nm as obtained from TEM (Figure S1, Supporting Information File 1). All samples were prepared using the same protocol as
Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles
Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259
- 10 µm wide gold electrodes spaced by 10 µm. Their height is 150 nm. Strips made of gold nanoparticles are deposited through SG-CSA, perpendicular to the IDE with the purpose of electrically connecting them. Five gold nanoparticle strips were fabricated, spaced by 100 µm. The optical microscopy image
- presented in Figure 2b displays the IDE gold electrodes that are connected by gold nanoparticle strips. The zoom in AFM image (Figure 2c) shows that the gold nanoparticle strips adopted an elongated shape near the gold electrodes, in agreement with the fact that the meniscus is deformed by topographical
- (C19H19N7O6) were purchased from Sigma-Aldrich. Gold interdigitated electrodes (IDE) were purchased from Dropsens. Gold nanoparticle synthesis and stabilization: Colloidal gold nanoparticles (AuNPs) were synthesized by the aqueous reduction of HAuCl4 with trisodium citrate. An amount of 100 mL of 10−3 M
Au nanoparticle-based sensor for apomorphine detection in plasma
Beilstein J. Nanotechnol. 2015, 6, 2224–2232, doi:10.3762/bjnano.6.228
- ]. In this work, we report on the use of gold nanoparticle (NP) arrays deposited on standard glass substrates to quantitatively detect apomorphine (APO) aiming at the realization of a biomedical sensor. APO has been long used in the treatment of patients with complicated Parkinson’s disease (PD). Indeed
Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol
Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209
- of their unique optical, electronic and catalytic properties [5][6][7][8]. Conducting polymer–gold nanoparticle composites exhibit improved physical and chemical properties over their single-component counterparts and are the focus of intensive research [9][10][11][12]. In the case of sensors, it has
- of polymer and metal from two separate solutions [20][21] or by electrodeposition of both components from one solution containing a monomer and a metal salt [17]. Finally, layers of electrodeposited polypyrrole and gold nanoparticle films can also been obtained from a single solution where PPy chains
Focused particle beam-induced processing
Beilstein J. Nanotechnol. 2015, 6, 1883–1885, doi:10.3762/bjnano.6.191
- for the patterning of gold nanoparticle structures is introduced by Takahiro Noriki and coworkers [9]. The resolution limiting aspects are covered in the article by Roland Schmied and collaborators concerning fundamental edge-broadening effects in FEBID [10]. A more recent development that may help to
The eNanoMapper database for nanomaterial safety information
Beilstein J. Nanotechnol. 2015, 6, 1609–1634, doi:10.3762/bjnano.6.165
- , where relevant. NMs are considered a special case of substances. Figure 3 shows the eNanoMapper prototype database user interface displaying the components of a gold nanoparticle with an organic coating. The visualisation is implemented as a JavaScript widget, which consumes the substance API. The
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
- characterized by SEM. The particle size and size distribution of the gold and silver nanoparticles are summarized in Figure 1c,d. This shows that the gold nanoparticle diameter distribution ranges from 5 to 30 nm with a maximum at 15 nm. The effect of clustering of the nanoparticles is observed upon drying of
- the bubbles. Figure 3a shows the optical limiting response for the gold nanoparticle and the gold/silica nanocomposite dispersions. For the gold nanoparticle dispersion, the optical limiting threshold is about 6.2 J/cm2. For the gold/silica nanocomposite dispersion, the optical limiting effect
- gold/silica nanocomposites than for the pure gold nanoparticle dispersion. Figure 3c,d shows the optical limiting response and normalized transmittance curves of silver nanoparticles and silver/silica nanocomposites. By adding the silica microspheres, the optical limiting threshold is lowered from 5.4
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
- 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
- adsorption to the sperm membrane seems surprising though, since albumins have been described to adsorb to the sperm membrane [70]. As the adsorption of albumins to the surface of gold nanoparticles can induce conformational changes though [71], the surface moieties diplayed by the BSA–gold nanoparticle
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
- similar uptake behavior compared to the OCH3-functionalized gold colloids, indicating a clathrin- and macropinocytosis-dependent mechanism (Figure 7b). Our analysis of uptake mechanisms of different gold nanoparticle formulations confirms literature data, in which a clathrin- and macropinocytosis
- elongated shape of gold nanoparticle rods and gold@metal oxide Janus particles leads to a stronger reduction in cell metabolic activity. 2) Endothelial cells react sensitively towards positively charged surfaces, e.g., caused by the surfactants NH2 and CyA. 3) Internalization of nanoparticles is driven by a
Mechanical properties of MDCK II cells exposed to gold nanorods
Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21
- epithelial cells was shown to be corrupted by gold-nanoparticle exposure in these previous publications, we decided to monitor viscoelastic changes and metabolically driven shape fluctuations in real-time by means of acoustic and impedance-based sensors like QCM and ECIS; the latter furthermore enabled us to
- distance curves For AFM measurements cells were seeded onto conventional glass slides. After reaching confluency, cells are exposed to different gold nanoparticle concentrations and surface modifications for 24 h. AFM imaging was performed on a Nanowizard II AFM (JPK Instruments AG, Berlin, Germany
Functionalization of α-synuclein fibrils
Beilstein J. Nanotechnol. 2015, 6, 124–133, doi:10.3762/bjnano.6.12
- attach to one fibril, when two neutravidin molecules that are present on the surface of gold nanoparticle bind to biotin moieties on the same fibril. The application of the biotin–streptavidin (avidin) interaction, which is known to be one of the strongest interactions in nature, offers a broad range of
- ). Biotinylated fibrils were incubated with neutravidin-conjugated 10 nm gold nanoparticles (Nanopartz, USA). Assuming that one neutravidin-conjugated gold nanoparticle can interact with 8 biotins, an appropriate volume of a nanoparticle suspension was added to the biotinylated fibril mixture to achieve an 8-fold
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
- dermal fibroblast cells (HDF) on gold nanoparticle-patterned surfaces for almost 10 h using optical dark field microscopy [14]. The authors found that the sedimented nanoparticles were collected by the cells during movement, which is clearly seen by a trail free of particles left behind. This property
- nitrogen flow and coated with a 15 nm thick gold layer. Cells were examined with a Leo Supra 55VP SEM (Zeiss, Oberkochen, Germany) at a voltage of 200 kV. Growth of epithelial cells on a gold nanoparticle-decorated substrate. (A) Optical dark field microscopy detects light scattered by the sample. Gold
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