Gold nanoparticles embedded in a polymer as a 3D-printable dichroic nanocomposite material

• Lars Kool,
• Anton Bunschoten,
• Aldrik H. Velders and
• Vittorio Saggiomo

Beilstein J. Nanotechnol. 2019, 10, 442–447, doi:10.3762/bjnano.10.43

• way, 3D objects. Results: In this paper we show how to fabricate a 3D-printable nanocomposite composed of dichroic gold nanoparticles and a 3D-printable polymer. The minute amount of gold nanoparticles used for obtaining the dichroic effect does not influence the mechanical properties of the polymer

• , for example, for the 3D fabrication of optical filters. Keywords: 3D printing; dichroism; gold nanoparticles; nanocomposite; Introduction As evidenced by paleolithic cave paintings [1], humans have always been fascinated by colors. Next to the traditional inorganic and organic colorants

• due to gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) of different sizes and shapes [9][10]. However, only the Lycurgus cup, now stored in the British Museum, and six other broken pieces showing the same dichroic effect were found worldwide, hinting that the achievement of such an optical

Thermal control of the defunctionalization of supported Au₂₅(glutathione)₁₈ catalysts for benzyl alcohol oxidation

• Zahraa Shahin,
• Hyewon Ji,
• Rodica Chiriac,
• Nadine Essayem,
• Franck Rataboul and
• Aude Demessence

Beilstein J. Nanotechnol. 2019, 10, 228–237, doi:10.3762/bjnano.10.21

• . However, the decrease in catalytic activity of (A400), with a lower TOF value (123 h−1), though it was fully defunctionalized, is related to the sintering of the gold nanoparticles, where bigger 2.0 ± 0.7 nm particles were observed on the TEM images. This means that both the defunctionalization and the

• did not inhibit high catalytic activity, in contrast, it was enhanced, which was similar to a recent reported work [25]. The catalyst performance was compared to a catalyst synthesized by the deposition-precipitation method of gold nanoparticles on ZrO2 nanoparticles, compound (B). The average

• ). They both reached 90% conversion after 15 h. This shows that when gold nanoparticles have a diameter more than 2 nm, they act in a similar catalytic manner, but still have slower catalytic activity compared to the partially calcined composite material (A300) (Table 1). At the selectivity level of 50

Targeting strategies for improving the efficacy of nanomedicine in oncology

• Gonzalo Villaverde and
• Alejandro Baeza

Beilstein J. Nanotechnol. 2019, 10, 168–181, doi:10.3762/bjnano.10.16

• selective delivery to these organelles [49]. The peptide Lys–Asp–Glu–Leu (KDEL) has been anchored on gold nanoparticles loaded with siRNA for the selective delivery of the genetic material into the endoplasmic reticulum [50]. The main mechanism for the internalization of nanoparticles within mammalian cells

Sputtering of silicon nanopowders by an argon cluster ion beam

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Zhenguo Wang,
• Wenbin Zuo,
• Sergey Belykh,
• Alexander Tolstogouzov,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2019, 10, 135–143, doi:10.3762/bjnano.10.13

• bombardment of gold nanoparticles with radius R = 4 nm by 100 keV gold atoms. The sputter yields ranged from only a few sputtered atoms to complete particle disintegration. Järvi et al. [17][18] have shown that the highest sputtering yield of gold nanoparticles by 25 keV gallium or 200 keV argon beams is

• [22]. Sputtering experiments have been performed mostly for gold nanoparticles and nanorods. Klimmer et al. [23] have studied the sputtering of gold nanoparticles with a radius of 3.6 nm on a sapphire substrate irradiated with 200 keV Ar ions. Their model predicts a strong size effect of the

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• -optical performance is doping them with nanoparticles. Hsu et al. showed that the small addition of gold nanoparticles decreases Uth due to the increased electric anisotropy and decreased elastic constant [5]. Haraguchi and collaborators doped the twisted nematic liquid crystal cell with inorganic

Colloidal chemistry with patchy silica nanoparticles

• Pierre-Etienne Rouet,
• Cyril Chomette,
• Laurent Adumeau,
• Etienne Duguet and
• Serge Ravaine

Beilstein J. Nanotechnol. 2018, 9, 2989–2998, doi:10.3762/bjnano.9.278

• calculated based on a minimum of 500 nanoparticles per batch using the following equation: where and are the number-average and the weight-average diameter, respectively, and ni is the number of particles of diameter Di. Synthesis of the Au@SiO2 nanoparticles Gold nanoparticles of 14 ± 2 nm were prepared

• by the citrate-reduction method reported by Turkevich [29]. SiO2 coating was carried out after surface functionalization of the gold nanoparticles by using a PEG-SH (Mw = 5000) aqueous solution in a similar manner as described in [23]. The surface modification allowed for the replacement of the

• citrate molecules adsorbed onto the gold surface by PEG-SH. A ratio of four PEG molecules per square nanometer of available surface of the gold sol was fixed. The aqueous solution of PEG-SH was freshly prepared and added dropwise to the as-prepared gold nanoparticles under vigorous magnetic stirring. The

Hybrid Au@alendronate nanoparticles as dual chemo-photothermal agent for combined cancer treatment

• Anouchka Plan Sangnier,
• Romain Aufaure,
• Laurence Motte,
• Claire Wilhelm,
• Erwann Guenin and
• Yoann Lalatonne

Beilstein J. Nanotechnol. 2018, 9, 2947–2952, doi:10.3762/bjnano.9.273

• with the same molecule used as reductant, coating and therapeutic agent has been developed in a one-pot, one-phase process using alendronate, a drug from the bisphosphonate family known for its antitumor effects. In addition, the core made of gold nanoparticles (NPs) brings thermal functionalities

• , with an IC50 value of 100 µM. Under NIR irradiation a temperature increase was observed leading to a reduction of the IC50 value to 1 µM, with total tumor cell death at 100 µM. Keywords: alendronate; bisphosphonate; cancer treatment; gold nanoparticles; photothermia; Findings Bisphosphonates (BPs

Comparative biological effects of spherical noble metal nanoparticles (Rh, Pd, Ag, Pt, Au) with 4–8 nm diameter

• Alexander Rostek,
• Marina Breisch,
• Kevin Pappert,
• Kateryna Loza,
• Marc Heggen,
• Manfred Köller,
• Christina Sengstock and
• Matthias Epple

Beilstein J. Nanotechnol. 2018, 9, 2763–2774, doi:10.3762/bjnano.9.258

• human cells [24][26][27], whereas in other studies, these effects were not observed [28][29][30]. With ultrasmall gold nanoparticles and gold clusters, different biological events are triggered that can lead to a higher cytotoxicity of very small particles (<3 nm) [31]. Very little is known about the

• ]. Platinum nanoparticles can be obtained by metal carbonyl-mediated synthesis in organic solvents [81]. Nanoscale platinum catalysts were synthesized using NaBH4 in octylamine [82]. Small gold nanoparticles (<10 nm) can be produced by wet-chemical approaches using strong reductants (e.g., NaBH4) in the

• ppm. In particular, no negative effect was observed for rhodium, palladium, platinum, and gold nanoparticles up to 50 ppm, indicating that no oxidative release of ions occurs. We conclude that there is no adverse effect of nanoparticles of these very noble metals on the cells because they are

Silencing the second harmonic generation from plasmonic nanodimers: A comprehensive discussion

• Jérémy Butet,
• Gabriel D. Bernasconi and
• Olivier J. F. Martin

Beilstein J. Nanotechnol. 2018, 9, 2674–2683, doi:10.3762/bjnano.9.250

• ], especially regarding the role of the SH source distribution over nanostructure surfaces. On the other hand, SHG was used to monitor the gap distance between gold nanoparticles and gold films [47]. The present study underlines the fact that the relationship between SHG and field enhancement in nanogaps is not

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• was revealed that the volume around gold nanoparticles where the permittivity is near zero, ε ≈ 0, accounts for the strongest absorption, which leads to the effective enhancements of X-ray emission. Keywords: double pulse; gold nanoparticles; intense femtosecond laser; plasma; water; X-ray

• laser and plasmonic nanoparticles will contribute to a broad field of applications ranging from pulsed X-ray generation to energetic particle sources [14] or terahertz wave emission from aqueous solutions [16]. In recent experimental studies, intense fs-laser excitation of plasmonic gold nanoparticles

• the optimization of enhancement in X-ray generation from an aqueous solution flow of plasmonic gold nanoparticles under fs-double-pulse excitation in air. The optimization of the solution film surface position with respect to the focal position of irradiation was systematically investigated for the

Au–Si plasmonic platforms: synthesis, structure and FDTD simulations

• Anna Gapska,
• Marcin Łapiński,
• Paweł Syty,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2018, 9, 2599–2608, doi:10.3762/bjnano.9.241

• rectangle – outer border of the sensors; brown circles – gold nanoparticles. Right: Side view, xy-plane; vellow line – light source, wave propagation in upward direction; red and brown lines – sensors for FDTD and FDTD/DFT simulation sets, respectively; light-blue area – air; yellow area – silicon; brown

• circles – gold nanoparticles. Calculated intensity distribution of the electromagnetic field with unpolarized incident light of a wavelength of 395 nm, integrated 10 nm above the Si surface. Calculated amplitudes of the components of the electromagnetic field with unpolarized incident light of a

Enhanced antineoplastic/therapeutic efficacy using 5-fluorouracil-loaded calcium phosphate nanoparticles

• Shanid Mohiyuddin,
• Saba Naqvi and
• Gopinath Packirisamy

Beilstein J. Nanotechnol. 2018, 9, 2499–2515, doi:10.3762/bjnano.9.233

• both in vitro and in vivo studies [5]. Gold nanoparticles conjugated with a trans-activating transcriptional activator (TAT) peptide modification encapsulated with the drug doxorubicin showed enhanced toxicity in brain cancer models [6]. Further, mesoporous silica nanoparticles were successfully used

High-throughput micro-nanostructuring by microdroplet inkjet printing

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222

• the nanoscale, so far it has been inefficient in generating a hierarchical overlay structure at the micrometer scale. Here, we show that by combining block copolymer micelle nanolithography with inkjet printing, hierarchical patterns of gold nanoparticles in the form of microstructures can be achieved

• in a high-throughput process. Inkjet printing was used to generate droplets of the micelle solution on surfaces, resulting in printed circles that contain patterns of gold nanoparticles with an interparticle spacing between 25 and 42 nm. We tested this method on different silicon and nickel–titanium

• surfaces and the generated patterns were found to depend on the material type and surface topography. Based on the presented strategy, we were able to achieve patterning times of a few seconds and produce quasi-hexagonal micro-nanopatterns of gold nanoparticles on smooth surfaces. Hence, this method is a

Surface energy of nanoparticles – influence of particle size and structure

• Dieter Vollath,
• Franz Dieter Fischer and
• David Holec

Beilstein J. Nanotechnol. 2018, 9, 2265–2276, doi:10.3762/bjnano.9.211

• a further example for theoretically derived values for the surface energy γ, Figure 5 displays the surface energy of gold nanoparticles as a function of the particle diameter [26]. These values were obtained using a function of the type of Equation 6. As was discussed in context with Equation 6

• particle size. Possibly, this is a result of the formation of a liquid-like layer at the surface. The results of the molecular dynamics calculations of Holec et al. [54] for the surface energy of spherical gold nanoparticles, depicted in Figure 13, are quite comparable with the values published by Ali et

• may be recommended to use data for the bulk material when data for the equivalent nanomaterial is not available. Melting temperature of gold nanoparticles according to Castro et al. [11] and Cluskey et al. [13]. One realizes two ranges in the data of Castro et al.: Within the experimental error bar

Fabrication of photothermally active poly(vinyl alcohol) films with gold nanostars for antibacterial applications

• Mykola Borzenkov,
• Maria Moros,
• Claudia Tortiglione,
• Serena Bertoldi,
• Nicola Contessi,
• Silvia Faré,
• Angelo Taglietti,
• Agnese D’Agostino,
• Piersandro Pallavicini,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2018, 9, 2040–2048, doi:10.3762/bjnano.9.193

• , Piazza dell’AteneoNuovo, 20126, Milan, Italy 10.3762/bjnano.9.193 Abstract The unique photothermal properties of non-spherical gold nanoparticles under near-infrared (NIR) irradiation find broad application in nanotechnology and nanomedicine. The combination of their plasmonic features with widely used

• antibacterial films and coatings. Keywords: antibacterial properties; gold nanostars; photothermal effect; poly(vinyl alcohol) films; Introduction The photothermal properties of non-spherical gold nanoparticles possessing localized surface plasmon resonance (LSPR) located in NIR range has already been

• materials that can coat surfaces and are capable of eradicating biofilms with remote physical activation. Even though gold nanoparticles are not intrinsically antibacterial, the thermal relaxation upon NIR light activation can be a major force of antibacterial action as it was shown for monolayers of GNSs

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• crystalline gold nanoparticles can be described by an effective scaling exponent of approximately half this value. This difference can be understood simply by considering how force cancellation effects become less effective for amorphous interfaces with irregular positioning of slider atoms [46]. While the

Self-assembled quasi-hexagonal arrays of gold nanoparticles with small gaps for surface-enhanced Raman spectroscopy

• Emre Gürdal,
• Simon Dickreuter,
• Fatima Noureddine,
• Pascal Bieschke,
• Dieter P. Kern and
• Monika Fleischer

Beilstein J. Nanotechnol. 2018, 9, 1977–1985, doi:10.3762/bjnano.9.188

• University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany 10.3762/bjnano.9.188 Abstract The fabrication and optical characterization of self-assembled arrangements of rough gold nanoparticles with a high area coverage and narrow gaps for surface-enhanced Raman spectroscopy (SERS) are reported

• . A combination of micellar nanolithography and electroless deposition (ED) enables the tuning of the spacing and size of the noble metal nanoparticles. Long-range ordered quasi-hexagonal arrays of gold nanoparticles on silicon substrates with a variation of the particle sizes from about 20 nm to 120

• near-field-enhanced bio-analytics of molecules. SERS was demonstrated by measuring Raman spectra of 4-MBA on the gold nanoparticles. It was verified that a smaller inter-particle distance leads to an increased SERS signal. Keywords: block copolymer; electroless deposition; gold nanoparticles; micelle

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• slide–hold–slide experiments on the time scale of seconds, similar to the development of grain boundaries in the fusion of gold nanoparticles [16]. In our experiments, the holding time before sliding was varied between 252 μs (v = 3.1 μm·s−1) and 100 s. As our system was drifting by only one atomic

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices

• T. Anh Thu Do,
• Truong Giang Ho,
• Thu Hoai Bui,
• Quang Ngan Pham,
• Hong Thai Giang,
• Thi Thu Do,
• Duc Van Nguyen and
• Dai Lam Tran

Beilstein J. Nanotechnol. 2018, 9, 771–779, doi:10.3762/bjnano.9.70

• response/recovery times. The various origins of these properties are commonly assigned to the following two phenomena: (i) a surface plasmon resonance (SPR) effect of plasmonic gold nanoparticles (Au NPs) could certainly take place and contribute to the electrical transport behavior for Au-decorated ZnO

• -micrometer ZnO spheres on the glass substrates were washed several times with deionized water, ethanol and dried at 80 °C. For incorporation of gold nanoparticles, a 0.025 mM aqueous solution of HAuCl4 was used. The ZnO films were immersed into this precursor solution. The reaction mixture was constantly

Dynamic behavior of nematic liquid crystal mixtures with quantum dots in electric fields

• Emil Petrescu,
• Cristina Cirtoaje and
• Octavian Danila

Beilstein J. Nanotechnol. 2018, 9, 399–406, doi:10.3762/bjnano.9.39

• well as science and engineering, requires improved technologies and new materials. Materials science provides great opportunities to these technologies by synthesizing new nanoparticles that can be mixed with liquid crystals: carbon nanotubes [1][2][3], graphene, magnetic nanoparticles [4][5], gold

• nanoparticles [6], quantum dots (QDs) [7][8][9][10][11][12] or other nanomaterials [13][14][15][16][17] that can be effectively used in electro-optical devices. When added to liquid crystals, quantum dots may seriously influence their behavior under an electric field due to the anchoring forces acting on the

Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• , Warsaw, Poland 10.3762/bjnano.8.278 Abstract Thermo- and electro-optical properties of a photonic liquid crystal fiber (PLCF) enhanced by the use of dopants have been investigated. A 6CHBT nematic liquid crystal was doped with four different concentrations of gold nanoparticles (NPs), 0.1, 0.3, 0.5 and

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• , requires temperatures that depend on the particle size and binding strength of the ligand [44]. For example, short alkanethiols allowed for the sintering of gold nanoparticles (Au NPs) at temperatures smaller than 150 °C [45], far below the typical gold sintering temperatures of 200–350 °C [35][36]. It is

• thiolates increased when decreasing the number of saturated units [58]. A different study found that π–π-stacking of phenyl groups in films of phenylethylthiolate-stabilized gold nanoparticles determined the interparticle separation and regulated charge transfer. The short ligand chain and the aromatic

• particles and the aliphatic chains stabilize the particles sterically; steric repulsion was strong enough only for chains above twelve carbon atoms to prevent rapid coalescence of the nanoparticles [28]. Karg et al. prepared gold nanoparticles in aqueous solutions and transferred them to chloroform and

Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass

• Nikolay Nedyalkov,
• Mihaela Koleva,
• Nadya Stankova,
• Rosen Nikov,
• Mitsuhiro Terakawa,
• Yasutaka Nakajima,
• Lyubomir Aleksandrov and
• Reni Iordanova

Beilstein J. Nanotechnol. 2017, 8, 2454–2463, doi:10.3762/bjnano.8.244

• -dimensional structures comprised of gold nanoparticles in glass. The sample material was gold-ion-doped borosilicate glass prepared by conventional melt quenching. The nanoparticle growth technique consisted of two steps – laser-induced defect formation and annealing. The first step was realized by

• , the color of the irradiated areas changed to pink, with a corresponding well-defined peak in the absorbance spectrum. We relate this effect to the formation of gold nanoparticles with optical properties defined by plasmon excitation. Their presence was confirmed by high-resolution TEM analysis. No

• glass sample. This technique can be used for the preparation of 3D nanoparticle systems embedded in transparent materials with potential applications in the design of new optical components, such as metamaterials and in plasmonics. Keywords: 2D and 3D nanoparticle fabrication; gold nanoparticles in

Increasing the stability of DNA nanostructure templates by atomic layer deposition of Al₂O₃ and its application in imprinting lithography

• Hyojeong Kim,
• Kristin Arbutina,
• Anqin Xu and
• Haitao Liu

Beilstein J. Nanotechnol. 2017, 8, 2363–2375, doi:10.3762/bjnano.8.236

• Al2O3 onto the nanostructures followed by thermal annealing [36]. In addition to the 2D pattern transfer processes, gold nanoparticles with specified 3D shapes were synthesized by growing seed particles in the internal cavities of 3D DNA nanostructures [37][38]. Compared to the above developments, there

Fabrication of gold-coated PDMS surfaces with arrayed triangular micro/nanopyramids for use as SERS substrates

• Jingran Zhang,
• Yongda Yan,
• Peng Miao and
• Jianxiong Cai

Beilstein J. Nanotechnol. 2017, 8, 2271–2282, doi:10.3762/bjnano.8.227

• intensity of probe molecules can be enhanced by employing a thinner gold film. Figure 10 shows AFM images of PDMS substrates coated 10 and 50 nm thick gold films. Compared to the gold film thickness of 50 nm, more gold nanoparticles are generated on the PDMS surface with a gold film thickness of 10 nm, as

• addition, the local EM field can be enhanced further by reducing the gap between adjacent nanoparticles and the largest enhancement was observed with a dense surface of nanoparticles. Figure 11 shows an AFM image of the commercial Q-SERS substrate (gold nanoparticles coated on a 5 × 5 mm2 silicon wafer

• glass. A further advantage is that laser light can pass through the polymer substrate and reach the nanoparticle layer to activate the plasmon resonance, which generates the enormous SERS enhancement. A SERS substrate with good transparency and flexibility was prepared as a self-assembly of gold