Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

• Joseba Irigoyen,
• Nikolaos Politakos,
• Eleftheria Diamanti,
• Elena Rojas,
• Marco Marradi,
• Raquel Ledezma,
• Layza Arizmendi,
• J. Alberto Rodríguez,
• Ronald F. Ziolo and
• Sergio E. Moya

Beilstein J. Nanotechnol. 2015, 6, 2310–2318, doi:10.3762/bjnano.6.237

• condenser-objective lens type S-TWIN (with an spherical aberration Cs ≈ 1.25 mm). The images were acquired with a CCD camera of samples prepared from water dispersions cast on lacey carbon grids. X-ray diffraction XRD data for GO were obtained using a Siemens D-5000 operated at 35 kV and 25 mA and Cu Kα

Paramagnetism of cobalt-doped ZnO nanoparticles obtained by microwave solvothermal synthesis

• Jacek Wojnarowicz,
• Sylwia Kusnieruk,
• Tadeusz Chudoba,
• Stanislaw Gierlotka,
• Witold Lojkowski,
• Wojciech Knoff,
• Malgorzata I. Lukasiewicz,
• Bartlomiej S. Witkowski,
• Anna Wolska,
• Marcin T. Klepka,
• Tomasz Story and
• Marek Godlewski

Beilstein J. Nanotechnol. 2015, 6, 1957–1969, doi:10.3762/bjnano.6.200

• dispersions in ethylene glycol after microwave solvothermal synthesis. (c) Photographs of nanoparticle dispersions in ethylene glycol after sedimentation. XRD patterns for Zn1−xCoxO nanopowders before annealing, with a nominal Co content in solution of 0, 1, 5, 10, and 15 mol %. XRD patterns for Zn1−xCoxO

Temperature-dependent breakdown of hydrogen peroxide-treated ZnO and TiO₂ nanoparticle agglomerates

• Sinan Sabuncu and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 1897–1903, doi:10.3762/bjnano.6.193

• surface of the NPs [11][12][13][14][15]. Another external factor, temperature, can be utilized for this purpose. In this respect, in several studies, the temperature-dependent viscosity of nanofluids (which could be defined as solid–liquid materials established by the NP dispersions in the range of 1–100

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• dispersions. Experimental techniques The X-ray powder diffraction data were collected from an X'Pert MPD diffractometer (Panalytical AXS) with a goniometer radius of 240 mm and using Cu Kα radiation (λ = 0.15418 nm). The average particle size was calculated from the line broadening using the Debye–Scherrer

• Mn:ZnS/ZnS and Mn:ZnS/ZnS/Fe3O4 (1), (1.5), (2) and (3) nanocrystals. (c) Digital photograph of colloidal dispersions of Mn:ZnS/ZnS/Fe3O4 nanocrystals with increasing Fe3O4 shell thickness. (a–d) Magnetization loops of fluorescent, magnetic nanocrystals Mn:ZnS/ZnS/Fe3O4 (1, 1.5, 2 and 3). The units of

Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition

• Klara Altintoprak,
• Axel Seidenstücker,
• Alexander Welle,
• Sabine Eiben,
• Petia Atanasova,
• Nina Stitz,
• Alfred Plettl,
• Joachim Bill,
• Hartmut Gliemann,
• Holger Jeske,
• Dirk Rothenstein,
• Fania Geiger and
• Christina Wege

Beilstein J. Nanotechnol. 2015, 6, 1399–1412, doi:10.3762/bjnano.6.145

• inorganic particles, the physical stability of dispersions increases with the magnitude of the ZP. That is, highly negative or highly positive ZPs typically both result in stable suspensions [81][82] due to Coulomb repulsion. The organic TMV template structures thus behaved analogously, with the

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• (vinylpyrrolidone) (PVP). This ligand efficiently replaces the citrate, as previously demonstrated for gold nanoparticles [32]. A purification of the nanoparticles to remove the synthesis byproducts was achieved by multiple ultracentrifugation steps and did not affect the stability of the dispersions. The alloyed

• nanoparticles themselves [9][40][41], it is important to separate the toxic effects of the nanoparticles and unreacted material from the synthesis [11][42]. As some reported cell culture experiments with alloyed silver–gold nanoparticles were conducted without purification of the dispersions [19][43][44], it

• microscopy (TEM) images were recorded with a Philips CM 200 FE instrument. The dispersions were diluted with deionized water, drop cast onto a carbon-coated copper grid and dried under ambient conditions. The particle diameter was estimated by manually measuring 50 particles and compiling a histogram

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• nonlinear refraction. Experimental Materials The nanoparticle dispersions were fabricated by the LAL technique as schematically shown in Figure 1a. A solid target material was placed at the bottom of a beaker and immersed in 10 mL of deionized (DI) water. A fiber laser with a wavelength of 1064 nm, a pulse

• material dispersions were placed in a glass cuvette with a light path of 1 mm for the optical limiting measurement. The incident and transmitted laser powers were measured. Results and Discussion The nanoparticle dispersions of different materials were fabricated by LAL as shown in Figure 1a. LAL is an

• ]. Figure 1b shows a photograph of the laser-generated gold and silver nanoparticle dispersions fabricated by the LAL technique. Droplets of the nanoparticle colloidal solution were placed on a polished silicon substrate. These droplets were dried and the nanoparticles on the silicon substrate were

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

• Shawn Sanctis,
• Rudolf C. Hoffmann,
• Sabine Eiben and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2015, 6, 785–791, doi:10.3762/bjnano.6.81

• colloidal nanoparticle dispersions [15][16]. In order to assist the in situ deposition of nanoparticulate zinc oxide onto the wt TMV template, mild microwave synthesis conditions for the zinc oximate precursor were used by us for the first time. Herein, we report on the fabrication of a functional hybrid

Observation of a photoinduced, resonant tunneling effect in a carbon nanotube–silicon heterojunction

• Carla Aramo,
• Antonio Ambrosio,
• Michelangelo Ambrosio,
• Maurizio Boscardin,
• Paola Castrucci,
• Michele Crivellari,
• Marco Cilmo,
• Maurizio De Crescenzi,
• Francesco De Nicola,
• Emanuele Fiandrini,
• Valentina Grossi,
• Pasqualino Maddalena,
• Maurizio Passacantando,
• Sandro Santucci,
• Manuela Scarselli and
• Antonio Valentini

Beilstein J. Nanotechnol. 2015, 6, 704–710, doi:10.3762/bjnano.6.71

• superficial current dispersions during electrical measurements. In the bottom part of the silicon wafer, a thin n+ implanted layer ensures ohmic contact between the silicon and the metallic Ti/Pt electrodes, covering the entire back surface (Figure 1b). Thus, the main differences between the FBK substrate

Pulmonary surfactant augments cytotoxicity of silica nanoparticles: Studies on an in vitro air–blood barrier model

• Jennifer Y. Kasper,
• Lisa Feiden,
• Maria I. Hermanns,
• Christoph Bantz,
• Michael Maskos,
• Ronald E. Unger and
• C. James Kirkpatrick

Beilstein J. Nanotechnol. 2015, 6, 517–528, doi:10.3762/bjnano.6.54

• CytoTox 96® non-radioactive cytotoxicity assay (Promega, G1780) to determine lactate dehydrogenase (LDH) release following membrane disruption after 4 h exposure. The NP-dispersions were checked for assay-interferences in regard to the absorbance readings with the NP-dispersion alone and in combination

Filling of carbon nanotubes and nanofibres

• Reece D. Gately and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2015, 6, 508–516, doi:10.3762/bjnano.6.53

• well known that they can improve the mechanical and electrical properties of various dispersants [121][122][123][124]. However, the properties of the resulting materials prepared from dispersions of TCNSs filled with various materials have not been fully investigated. One interesting application area

Tunable light filtering by a Bragg mirror/heavily doped semiconducting nanocrystal composite

• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2015, 6, 193–200, doi:10.3762/bjnano.6.18

• reversible post-fabrication treatment. Once the composite is fabricated by coupling the NC dispersion or film to the Bragg mirror, tuning of the transmission is realized by applying chemical or electrochemical treatments, while keeping the concentration and thickness of the dispersions or films and the Bragg

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• -nitrobenzoic acid). The standard conditions for the determination of thiol groups, e.g., in molecules or proteins involve aqueous solutions and pH control [28]. This was, however, not applicable to the dispersions of silica NP because of increased agglomeration. We therefore performed the reaction in dry

• ) are occasionally observed in the reaction products. Since they occur in strongly varying amounts we cannot give a typical percentage for the degree of aggregation. They can be removed almost completely by centrifugation at low gravity from ethanol dispersions and may be of interest as models for the

• 640 nm, right). Scattering corrections to the experimental absorption spectra of labelled NP dispersions in ethanol. Left: MPD on the surface of silica NP (average diameter 105 nm, standard deviation 23 nm, 500–700 MPD molecules per particle); right: BPD in the core of silica-coated polyorganosiloxane

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• Farmaceutiche, University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy 10.3762/bjnano.5.242 Abstract The development of chemical strategies to render graphene viable for incorporation into devices is a great challenge. A promising approach is the production of stable graphene dispersions from the

• exfoliation of graphite in water and organic solvents. The challenges involve the production of a large quantity of graphene sheets with tailored distribution in thickness, size, and shape. In this review, we present some of the recent efforts towards the controlled production of graphene in dispersions. We

• of graphene into advanced functional materials forward. Keywords: applications; dispersions; graphene; organic functionalization; ultrasonication; Review Introduction Various methodologies for the production of graphene and chemically modified graphene have been described during the last years [1

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• for unprotected SWCNTs (381 n-type CNFETs) to 134 kΩ for protected SWCNTs (110 n-type CNFETs) (Figure 8d) [71]. The median value of the hysteresis width also narrowed from 2.2 V to 0.5 V (Figure 8e) [71]. In addition, the widths (see the insets in Figure 8d,e) of the dispersions of on-resistance and

Effect of silver nanoparticles on human mesenchymal stem cell differentiation

• Christina Sengstock,
• Jörg Diendorf,
• Matthias Epple,
• Thomas A. Schildhauer and
• Manfred Köller

Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214

• predict the possible health risks. Experimental Synthesis of silver nanoparticles Polyvinylpyrrolidone (PVP)-coated silver nanoparticles were synthesized by reduction with glucose in the presence of PVP as described previously [19][21]. The final silver concentration in all dispersions was determined by

Rapid degradation of zinc oxide nanoparticles by phosphate ions

• Rudolf Herrmann,
• F. Javier García-García and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2007–2015, doi:10.3762/bjnano.5.209

• dispersions are due to Zn2+ ions whose concentration is almost equal in any sample within three days at pH 7.6 [11]. However, another investigation showed a higher toxicity for smaller particles [12]. In addition, the toxicity to marine organism was found to be shape-dependent [13]. Toxicity seems to parallel

• course of the reaction of buffer B with the nanoparticles for one hour, the ζ-potential of all particle dispersions has a tendency to shift to more negative values, and the hydrodynamic diameter decreases (Table 2). Due to the highly irregular shape of the zinc phosphate particles and their varying

• [26]. The successful fluorescence labelling of ZnO-NP was checked by irradiating the dispersions at 254 nm. Dry solvents (stored over molecular sieves 4 Å) were used in all cases. Solvents and reagents were purchased from Merck unless otherwise noted. TEM pictures were taken with a JEM 2100 F

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• THOR Labs photodiode (Thorlabs PM100D with a silicon photodiode S120VC) was used to normalize the sample photocurrent to the incident light intensity for all the measurements in the vis–NIR region. Results and Discussion TEM images acquired at 120 kV of the spray dispersions obtained with both the

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• phenylated CNOs were not soluble in organic solvents, but sulfonation with oleum, followed by treatment with aqueous NaOH lead to a highly soluble product, which formed stable dispersions in water as well as in ethanol (Scheme 4B). The last reaction investigated was based on an earlier reported oxidation of

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• silver nanoparticles were chemically characterized, purified from synthesis by-products and the silver content in the dispersions was measured for each batch. Unless otherwise noted, in all cases in which silver nanoparticles are referred to in the following sections, they are PVP-coated with a negative

• have investigated whether STXM can be applied to investigate the cellular uptake process of silver nanoparticles in human mesenchymal stem cells (hMSC). For this purpose, hMSC were grown on collagen-coated Si3N4-membranes and incubated for 24 h with O2-free aqueous dispersions of silver particles (c

• efficiently accumulate silver nanoparticles in a process that increases their silver content proportional to the concentration of particles applied at least for incubations with silver nanoparticle dispersions containing silver concentrations of up to 300 µM (32.4 µg mL−1) [108]. After 4 h of incubation with

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

• Christoph Bantz,
• Olga Koshkina,
• Thomas Lang,
• Hans-Joachim Galla,
• C. James Kirkpatrick,
• Roland H. Stauber and
• Michael Maskos

Beilstein J. Nanotechnol. 2014, 5, 1774–1786, doi:10.3762/bjnano.5.188

• ], which orders ions according to the magnitude of their destabilizing effect on colloidal dispersions. Nevertheless, small amounts of salt should be added to the eluate in AF-FFF to minimize electrostatic repulsion [43]. For application in the fields of the bio-nano sciences, physiological salt contents

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• ways through chemical adsorption of ordered architectures [33][34] and preserve the extended networks of the CNTs seems therefore very attractive. In this review, starting from several examples of good dispersions and dispersants, we intend to systematically identify the features that allow a molecule

• provided by magnetic stirring, reflux, shear mixing, or, most commonly, ultrasonication either mild sonication in a bath or high-power sonication using a tip [16]. Once exfoliated, the simplest stable CNTs dispersions have been achieved by using solvent molecules able to efficiently interact with CNTs such

• mixing a negative value. However, NMP molecules could be removed by heating to 340 °C, leaving perfectly intact nanotubes and demonstrating that NMP was physisorbed via van der Waals interactions onto the nanotube surface. Good and relatively stable dispersions have been obtained also by sonicating CNTs

Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity

• Dickson Joseph,
• Nisha Tyagi,
• Christian Geckeler and
• Kurt E.Geckeler

Beilstein J. Nanotechnol. 2014, 5, 1452–1462, doi:10.3762/bjnano.5.158

• (Figure S1, Supporting Information File 1). Photographs of the dispersions (Figure S2, Supporting Information File 1) were taken after the microwave irradiation under different pH conditions, and the color characteristic of the AuNPs was observed only for reactions carried out at the intrinsic pH values

• . Whereas at acidic, neutral and basic pH conditions, different colored dispersions were observed, and detailed studies on their size and shape are in progress. Hence, varying the pH of the protein solution modifies the structural confirmation of the protein, which alters the native state of the amino acids

• IEPs of the protein-coated AuNPs, their aqueous dispersions were subjected to pH-dependent zeta potential titration studies. The AuNPs behavior in the human body can be understood by examining the correlation between pH and zeta potential. Figure 3 shows the results for the different protein-coated

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

• Dominic Docter,
• Christoph Bantz,
• Dana Westmeier,
• Hajo J. Galla,
• Qiangbin Wang,
• James C. Kirkpatrick,
• Peter Nielsen,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151

• methods. First, the size, spherical shape and homogeneity of the ASP were visualized by transmission electron microscopy (TEM) (Figure 1). Next, we examined the stability of the ASP dispersions in water, salt-containing buffer (buffer A), and cell culture medium (DMEM) with or without the addition of 10

• to link individual or multiple particle parameters, such as geometry, pore size or surface functionalization to the observed nanobiological effects. The negative zeta potential, hydrodynamic diameter and colloidal stability of the ASP dispersions were obtained in water, salt-containing buffer, and

• dispersions of ASP were purchased from Nyacol Nano Technologies (ASP20, ASP30, ASP100), Sigma (Sigma-Aldrich, Taufkirchen, Germany) (ASP30L) or Kisker Products (ASP30F, ASP30F-COOH) and used as received. The ASP were characterized with respect to shape, size, and size distribution in the dry state as well as

Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

• Fabian Herzog,
• Kateryna Loza,
• Sandor Balog,
• Martin J. D. Clift,
• Matthias Epple,
• Peter Gehr,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2014, 5, 1357–1370, doi:10.3762/bjnano.5.149

• vary from incorporations into materials such as for textile fabrics, medical devices, air filters, and food containers, to dispersions, e.g., for water disinfectants and cosmetics (e.g., deodorants), as well as many more commodities for ‘everyday use’ [7][8]. The application of Ag NPs leading to their

• kDa MWCO centrifugal filter units (Vivaspin 20; Sartorius Stedim AG, Tagelswangen, Switzerland) at 3000g by diafiltration for 10 min. The Ag NP dispersions were always freshly prepared before each individual experiment. Nanoparticle characterisation The size distribution and zeta potential of the Ag