Microwave synthesis of high-quality and uniform 4 nm ZnFe₂O₄ nanocrystals for application in energy storage and nanomagnetics

• Christian Suchomski,
• Ben Breitung,
• Ralf Witte,
• Michael Knapp,
• Sondes Bauer,
• Tilo Baumbach,
• Christian Reitz and
• Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

• narrow size distribution hold promise for many applications in different areas ranging from biomedicine to electronics and energy storage. Herein, the microwave-assisted sol–gel synthesis and thorough characterization of size-monodisperse zinc ferrite nanoparticles of spherical shape is reported. X-ray

• general formula MFe2O4 constitute a well-known class of materials with unique physical and chemical properties and they hold promise for use in various fields of nanotechnology [1][2]. One of those properties is magnetism. In recent years, it has been shown that particularly size-monodisperse

• diameter MFe2O4 (M = Fe, Co, Mn, Ni) nanoparticles has been achieved by microwave-assisted nonaqueous sol–gel synthesis using benzyl alcohol as a high-boiling solvent [22][23]. Inspired by this work, we show here that high-quality and size-monodisperse zinc ferrite (referred to as ZFO in the following

Straightforward and robust synthesis of monodisperse surface-functionalized gold nanoclusters

• Silvia Varela-Aramburu,
• Richard Wirth,
• Chian-Hui Lai,
• Guillermo Orts-Gil and
• Peter H. Seeberger

Beilstein J. Nanotechnol. 2016, 7, 1278–1283, doi:10.3762/bjnano.7.118

• discovered by serendipity. The resultant monodisperse gold nanoclusters are more stable than those generated using some other common methods. The carboxylic acid contained in the stabilizing agent on the cluster surface serves as anchor for nanocluster functionalization. Alternatively, the addition of thiols

• prepared under reflux using 1-thioglucose as reducing and stabilizing agent [24] but the resulting nanoparticles are too unstable to be used as biosensors [25]. In an effort to create monodisperse, stable and surface-functionalized gold nanoclusters, we explored 1-thioglucose as a stabilizing and reducing

• agent. By serendipity we discovered a novel one-pot method to prepare gold nanoclusters using 1-thioglucose at room temperature. This simple and robust synthesis produces stable, and monodisperse nanoclusters. Oxidation of the carbohydrate results in carboxylic acid as determined by X-ray photoelectron

Tunable longitudinal modes in extended silver nanoparticle assemblies

• Serene S. Bayram,
• Klas Lindfors and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2016, 7, 1219–1228, doi:10.3762/bjnano.7.113

• , unlike AgNP–cysteamine, higher ligand ratios are needed to initiate assembly. This is consistent with the spectral evolution depicted in Figure 1. 20 µm long assemblies were noticed for r = 3250 (Supporting Information File 1, Figure S4). For all samples, TEM shows a fairly monodisperse nanoparticle size

Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface

• Rebeca Ortega-Amaya,
• Yasuhiro Matsumoto,
• Andrés M. Espinoza-Rivas,
• Manuel A. Pérez-Guzmán and
• Mauricio Ortega-López

Beilstein J. Nanotechnol. 2016, 7, 1010–1017, doi:10.3762/bjnano.7.93

• arrows in Figure 4a. The FE-SEM images (Figure 4b,c) display the striking morphology of the sample prepared at 1000 °C. It consists of highly faceted core–shell Cu-rGO nanostructures and small, nearly monodisperse 3 nm in size, rGO-CuNPs, all of them decorating the rGO sheets. Some holes in the rGO

Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers

• Kai Rückriem,
• Sarah Grotheer,
• Henning Vieker,
• Paul Penner,
• André Beyer,
• Armin Gölzhäuser and
• Petra Swiderek

Beilstein J. Nanotechnol. 2016, 7, 852–861, doi:10.3762/bjnano.7.77

• rather homogeneous distribution of monodisperse NPs has been achieved by electron irradiation and subsequent washing of well-organized silver(I) dodecanethiolate layers [19]. Also, self-assembled layers can be prepared by simple wet-chemical dipping processes [21][22] or high-throughput spray

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• with hexagonal or lozenge-like particles differing in size is available. Even for particles of a uniform and simple shape like disks or squares, their maximum packing density is affected by their size distribution. For monodisperse disks in a hexagonal two-dimensional arrangement, a maximum packing

• density of 90.7% can be achieved [12]. For a square packing of monodisperse disks, the packing density is reduced to 79% [13]. For disks having a variation in size similar to the dispersion of CPE45 nanocrystals, no long range order can be achieved and a maximum packing density of about 84% is expected

• the order or the packing density of the nanocrystal film, which we attribute to random jamming of nanocrystals. We note that the area coverage of the CPE45 nanocrystal films was close to 82.6%, which is the area coverage where jamming of a monolayer of monodisperse, frictionless disks is expected [17

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• , nanosphere lithography offers the preparation of a self-assembled monolayer on the time scale of minutes even on a centimetre length scale. In this work, polystyrene(PS)-based nanosphere lithography was chosen, since monodisperse PS nanosphere suspensions are nowadays commercially available with a wide range

• self-assembly of monodisperse PS spheres on the chosen substrate; (b) the homogeneous reduction of the PS sphere diameter by setting the plasma etching time while maintaining their initial positions on the substrate. Then, the nanoscale masks are ready for the deposition of a magnetic film and a

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• water sorption isotherms measured for similar materials, indicating the different pressures for capillary condensation during adsorption and capillary evaporation during desorption, respectively, in pores with quite monodisperse size distributions [22]. It is well known that adsorption and desorption of

• the nanostructure characterization using GISAXS. The nanostructure of this material consists of quite monodisperse cylindrical pores ordered on 2D pore lattice [24]. The GISAXS pattern of the corresponding sample shown in Figure 3 reveals sharp Bragg reflections from this pore lattice. The fact that

Surface coating affects behavior of metallic nanoparticles in a biological environment

• Darija Domazet Jurašin,
• Marija Ćurlin,
• Ivona Capjak,
• Tea Crnković,
• Marija Lovrić,
• Michal Babič,
• Daniel Horák,
• Ivana Vinković Vrček and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 246–262, doi:10.3762/bjnano.7.23

• is known that intensity size distributions are subject to scattering interferences because the intensity of scatter light is much greater for large agglomerates compared to small particles. In accordance with the obtained DLS data, TEM images in UW showed monodisperse AOTAgNPs, PVPAgNPs, TweenAgNPs

Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• synthesized through a polyol synthesis, in the presence of poly(vinylpyrrolidone) (PVP) as a stabilizing agent, adopting an established literature protocol [35]. The resulting nanocube samples were mainly monodisperse with 45 nm average size and contained only a negligible fraction of Ag rods and irregular

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• the PDADMAC layer on the pH value during adsorption is shown in Figure 3. All particle samples show a monodisperse size distribution, indicated by a low polydispersity index (PDI ≤ 0.1). As expected, the nanoparticle size does not depend on the pH value during adsorption of PDADMAC, since the polymer

Two step formation of metal aggregates by surface X-ray radiolysis under Langmuir monolayers: 2D followed by 3D growth

• Smita Mukherjee,
• Marie-Claude Fauré,
• Michel Goldmann and
• Philippe Fontaine

Beilstein J. Nanotechnol. 2015, 6, 2406–2411, doi:10.3762/bjnano.6.247

• precursors. The radiolysis induced by reduction of metal ions is generally considered as an efficient method to control this synthesis in solution as it leads to the formation of monodisperse, tailored, metal nano-objects [3]. The synthesis route involves the irradiation of a metal-ion aqueous solution that

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• ionic surfactants can reduce the zeta potential of Ag NPs from −20 to −50 mV, which is favorable for stabilization. They concluded that non-ionic surfactants can form a layer with inhibition function to prevent the formation of other nuclei and consequently lead to monodisperse NPs [100]. Lu et al

An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

• solution. We extended this concept to clusters of nanoparticles, too. Results and Discussion In this work, we considered monodisperse systems of nanoparticles, with diameters of 7 nm and 17 nm and a constant anisotropy, and we simulated for various nanoparticle volume fractions ranging between 0.01 and

• concentration of nanoparticles increases. In clusters, SLP is lower with random orientations than with parallel orientations, for small as well as high diameters of nanoparticles (Figure 4). When simulating the SLP dependence on the nanoparticle size in a monodisperse system of uniformly distributed

Distribution of Pd clusters on ultrathin, epitaxial TiO_x films on Pt₃Ti(111)

• Christian Breinlich,
• Maria Buchholz,
• Marco Moors,
• Tobias Pertram,
• Conrad Becker and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

• [8][9][10] for example. In the ideal case, the clusters should be monodisperse or have at least a known size distribution. Ideal oxide surfaces can be favourably implemented in the form of thin epitaxial films. Such films grown on a single crystalline, metal support have several advantages: (a

NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials

• Katre Juganson,
• Angela Ivask,
• Irina Blinova,
• Monika Mortimer and
• Anne Kahru

Beilstein J. Nanotechnol. 2015, 6, 1788–1804, doi:10.3762/bjnano.6.183

• , crustaceans and mammalian cells in vitro Ivask et al. [39] showed that the toxicity of 20, 40, 60 and 80 nm monodisperse citrate-coated Ag NPs could fully be explained by released Ag ions whereas 10 nm Ag NPs proved more toxic than predicted. Analysis of the data in NanoE-Tox database revealed that the

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

• nanocrystals were nearly monodisperse and of spherical shape. The average diameter of these QDs was determined to be 3.8 ± 0.7 nm (Figure 3a,b,e). The TEM and HR-TEM micrograph of Mn:ZnS/ZnS/Fe3O4 (1.5) crystals shows almost spherical particles with an average size of 4.4 ± 0.9 nm (Figure 3c,d,f). The measured

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• important that the Fe3O4 nanoparticles are stable under physiological conditions that are necessary for biomedical applications, it is crucial to use controllable synthesis conditions in order to obtain monodisperse, uniform nanoparticles with desired properties [18]. Despite their low toxicity, fine

• this study to achieve the optimum results presented by the reaction: 2FeCl3 + FeCl2 + 8NaOH → Fe3O4(s) + 4H2O + 8NaCl. As the TEM image in Figure 1a shows, the typical uncoated Fe3O4 nanoparticles had an average diameter of 10 nm and were monodisperse and partially aggregated because of their magnetic

• biocompatible and nontoxic to the cells. Conclusion In summary, this study reports the preparation of two nanocomposites using a three step procedure. The monodisperse, uniform, Fe3O4 nanoparticles were synthesized through a co-precipitation method resulting in a diameter of about 10 nm, followed by surface

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

• ) 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

• size and morphology of the nanoparticles were determined by transmission electron microscopy (TEM), differential centrifugal sedimentation (DCS) and dynamic light scattering (DLS). TEM showed that the nanoparticles were nearly monodisperse, quasi-spherical, polycrystalline, and had a uniform diameter

• order to compare the samples, the total amount of metal was chosen as the fixed parameter. The actual nanoparticle concentration, shown in Table 3, was calculated on the basis of the measured nanoparticle diameter from DCS and the assumption that the particles are perfectly spherical and monodisperse

Experimental determination of the light-trapping-induced absorption enhancement factor in DSSC photoanodes

• Serena Gagliardi and
• Mauro Falconieri

Beilstein J. Nanotechnol. 2015, 6, 886–892, doi:10.3762/bjnano.6.91

• form a compact monolayer coating all the available titania surface. The available surface was calculated by representing the PA as a parallelepiped filled with titania spheres. In a simplified scheme, the nanoparticles were assumed to be monodisperse with a fixed packing density (0.64 according to [17

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

• cytotoxicity following interaction with lung surfactant, we investigated and compared aSNPs with three different surface modifications (aSNP–plain, –NH2, –COOH). Material and Methods Nanoparticles: Sicastar Red, which were already described in Kasper et al. [10][11] are monodisperse amorphous silica

• assumptions about sample properties (i.e., about size distribution), the data analysis method "Monodisperse" was used for the evaluation of the measurements. The results are summarized in Table 1. These results are comparable to previously reported data for particles of this manufacturer [10]: No significant

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

• Nils Bohmer and
• Andreas Jordan

Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16

• . Fluorescent silica coated iron oxide nanoparticles (SCIONs) SCIONs were provided and characterized by the National Institute of Health (Maryland, USA). They were monodisperse at pH 7 and had a hydrodynamic diameter of 17 nm with a surface charge of 50 ± 5 mV. For detection in confocal fluorescence microscopy

• nanoparticle suspensions, involvement of more than one specific pathway is not surprising. Endocytosis through Caveolin-1 and CDC42 is characterized by vesicles of 30 to 80 nm [27][28], which excludes bigger agglomerates from uptake. For future experiments monodisperse and well-defined particle species would

The distribution and degradation of radiolabeled superparamagnetic iron oxide nanoparticles and quantum dots in mice

• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Markus Heine,
• Christian Waurisch,
• Gordon M. Stachowski,
• Stephen G. Hickey,
• Alexander Eychmüller,
• Jörg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 111–123, doi:10.3762/bjnano.6.11

• isotopes and basic parameters regarding their biodistribution and degradation were studied. It was previously shown that oleic acid-stabilized, hydrophobic, monodisperse, iron oxide cores can easily incorporate water-free 59FeCl3 [24]. This results in the stable labeling of the core and allows a quasi “on

• appropriate radionuclide into the core or an inner shell during chemical synthesis in order to guarantee the full stability of the label. Experimental Nanoparticle synthesis Monodisperse, oleic acid-stabilized SPIOs were synthesized according to Yu et al. [43]. Briefly, a mixture of 2 mmol FeOOH, 8.0 mmol

• remove water and traces of hydrochloric acid. Next, previously synthesized, monodisperse, oleic acid-stabilized SPIOs were added (1 mg dry weight in 400 µL CHCl3). The solution was stirred at room temperature for at least 24 h before using the SPIOs for further experiments (i.e., embedding in lipid

Chemoselective silicification of synthetic peptides and polyamines

• Maryna Abacilar,
• Fabian Daus and
• Armin Geyer

Beilstein J. Nanotechnol. 2015, 6, 103–110, doi:10.3762/bjnano.6.10

• ] are in use today for the synthesis of largely monodisperse silica particles with entrapped enzymes for NMR studies [2] or numerous other applications [3]. Generally, one or more molecular species are exposed to orthosilicic acid at pH 7 or higher. Slow or inefficient precipitation is accompanied by

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• Chemistry, University Hamburg, Grindelallee 117, 20146 Hamburg, Germany Molecular and Cellular Oncology, ENT/University Medical Center Mainz, Langenbeckstr. 1, 55101 Mainz, Germany 10.3762/bjnano.6.5 Abstract A variety of monodisperse superparamagnetic iron oxide particles (SPIOs) was designed in which the

• used as model hydrophobic monodisperse iron oxide nanoparticles, obtained from a high-temperature synthesis, which were transferred into aqueous medium by encapsulation with the well-characterized amphiphilic polymer, poly(maleic anhydride-alt-1-octadecene) [24][25]. These particles are negatively

• ” [10]. In the present study we used polymer-coated monodisperse SPIOs (11 nm core, total hydrodynamic diameter about 25 nm), as well as PEGylated variants as model nanoparticles. The iron oxide cores were labelled with 59Fe and we used an iodination kit to label also transferrin or albumin with 125I to