Multiwalled carbon nanotube hybrids as MRI contrast agents

• Nikodem Kuźnik and
• Mateusz M. Tomczyk

Beilstein J. Nanotechnol. 2016, 7, 1086–1103, doi:10.3762/bjnano.7.102

• the realm of CNTs showed great potential but also the problems and imperfections that needed to be overcome. One of the first challenges was to reduce the tendency of CNTs for aggregation, which seriously affected the stability of their aqueous and buffered dispersions. Another issue was to enhance

• transformations [18]. Surprising results of the relaxation effects both in vitro and in vivo and depending on a number of parameters, such as content of the residual catalyst, size of the CNTs or "wrapping media" (the electrolyte used to stabilize the dispersions), were also reported [18][19]. We discuss these

• functionalization of the nanotubes changed in the dispersions. This method also allowed us to quantify the stability of different hybrids, e.g., the adsorption of Fe-L3-oMWCNT#Kuźnik and Fe-L4-MWCNT#Kuźnik decreased in the characteristic UV–Vis maximum by factors of 0.0097/h and 0.0147/h, respectively, over the 24

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

• semiconducting molecules. Results Nanocrystal analysis by AFM The model of an ideal CPE45 nanocrystal Nanocrystal dispersions were prepared via nanoprecipitation with the impact of shear forces generated by ultrasonication. By cryo-transmission electron microscopy (TEM) studies on the dispersions, a thickness of

• generated by injection of a hot THF solution of CPE45 into a solution of caesiumhydroxide at pH 12 and ultrasonicated for 10 min. The dispersion (initial polymer concentration ca. 1 mg/mL) was filtered through a syringe filter. The dispersions were annealed for five hours at 90 °C and cooled to room

• temperature over a period of one hour. The resulting nanocrystal dispersions were dialyzed for 30 min against an aqueous solution of potassium hydroxide at pH 11. Experiments with polyethylene surfaces decorated by carboxyl groups have shown that at least pH 11 is needed for complete ionization of the

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

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

• Brunella Perito,
• Emilia Giorgetti,
• Paolo Marsili and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2016, 7, 465–473, doi:10.3762/bjnano.7.40

• larger NPs (diameter 6.1 nm; σ− = 3.1 nm; σ+ = 6.4 nm) were statistically more prominent than smaller NPs (diameter 0.9 nm; σ− = 0.5 nm; σ+ = 1.2 nm), as reported in Figure 3b. Bacterial susceptibility to AgNPs The four Ag colloidal dispersions, as obtained from laser ablation, were used for the

• found with the MBC values, where the lowest values were obtained on both microorganisms with ps-ablated AgNPs in LiCl solution. In general, all of the colloids tested were more effective than the antibiotic tested as a reference (Table 2). After storing the AgNPs colloidal dispersions for about two

Efficiency improvement in the cantilever photothermal excitation method using a photothermal conversion layer

• Natsumi Inada,
• Hitoshi Asakawa,
• Taiki Kobayashi and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2016, 7, 409–417, doi:10.3762/bjnano.7.36

• reducing the graphite concentration in the dispersions. Coarse regulation of the excitation efficiency was possible by this method. However, fine regulation only by controlling the graphite concentration was difficult due to the difference in drop volumes formed by two glass probes and the inhomogeneity of

• colloidal graphite flakes in the dispersions. Owing to these reasons, it is difficult to estimate the accurate excitation efficiency only from the graphite concentration. To solve this problem, we found the relationship between the blackened area evaluated by optical microscopy and excitation efficiency. We

• process. The colloidal graphite concentration of the dispersions used in this study are shown in the caption of Figure 5. Sonication of the coating solution was performed before the coating process. The average diameter of colloidal particles in the coating solution was measured by the dynamic light

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

• Dinusha N. Udukala,
• Hongwang Wang,
• Sebastian O. Wendel,
• Aruni P. Malalasekera,
• Thilani N. Samarakoon,
• Asanka S. Yapa,
• Gayani Abayaweera,
• Matthew T. Basel,
• Pamela Maynez,
• Raquel Ortega,
• Yubisela Toledo,
• Leonie Bossmann,
• Colette Robinson,
• Katharine E. Janik,
• Olga B. Koper,
• Ping Li,
• Massoud Motamedi,
• Daniel A. Higgins,
• Gary Gadbury,
• Gaohong Zhu,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2016, 7, 364–373, doi:10.3762/bjnano.7.33

• nanoplatform dispersion (3.0 mg in 3.0 mL of PBS, see above) and 30 µL of each of the proteases at every concentration level in PBS. The dispersions were incubated at 25 °C for 60 min, followed by the recording of a fluorescence spectrum at 25 °C using a Fluoromax2 spectrometer (λem = 421 nm, λex = 620–680 nm

• the proteases at every concentration level in PBS. The dispersions were incubated at 25 °C for 60 min, followed by the recording of a fluorescence spectrum at 25 °C using a Fluoromax2 spectrometer (λex = 421 nm, λem= 620–680 nm). Inactivation of serum was achieved by heating to 56 °C in an incubator

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

• fluids [19][20][21][22][23][24][25][26][27]. NP agglomeration is intended in some applications, such as in immunoassays [28], while many others require stable colloidal dispersions of NPs at high physiological ionic strength [29]. Stabilization of metallic NPs at high electrolyte content, i.e., in

• CITAgNPs, PVPAgNPs and BSAAgNPs, the results clearly showed good colloidal stability, i.e., the size distributions in BM were similar to those obtained for dispersions in UW (Table 1). However, the absolute value of the ζ-potential for BSAAgNPs increased after dispersion in BM. Conversely, the ζ-potential

• BMP, as this protein is just slightly negatively charged at physiological pH values. The measured ζ-potentials were very close to the values determined for pure BSA dispersions, −7.5 ± 0.04 mV, which is not surprising taking into account the relatively high protein concentration. Thus, BSA conjugates

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• , and 3 indicate the number of PAH/graphene bilayers deposited. It can be seen from the data that all Ψ spectra almost coincide with each other, while the Δ spectra shift downwards upon deposition of bilayers of PAH/graphene(−)SDS. The thickness values (d) and dispersions, e.g., spectra of refractive

• thickness of the graphene–surfactant composite layer. While the dispersions of refractive index and extinction coefficient were modelled by a single Lorentzian peak lying in the IR region, the absorption peak of graphene at approximately 260 nm was outside the spectral range (370–1000 nm) of the

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

• Figure 1b. AgNC dispersion exhibits a sharp peak around 450 nm that, according to previous reports [41][42], can be ascribed to the LSPR of nanocubes with 50 nm edge size in agreement with our TEM results and our preliminary findings [21] on different nanocube dispersions. Two minor peaks (348 and 380 nm

• a different approach overlaying GO sheets on prepacked AgNC layers in the search for a reliable method that allows conjugation of AgNPs with desired morphologies (densities, sizes and shapes) with graphene oxide continuous covering. GO forms stable colloidal dispersions in water thanks to the

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

• particle dispersions were titrated with hydrochloric acid (25 mM). By plotting the zeta potential versus pH, the isoelectric point (IEP) can easily be determined. The IEP corresponds to a state of charge neutrality, where ζ is zero. Thus, it is an important parameter characterizing the pH region, in which

• . Therefore, PDADMAC solutions, as well as the PLGA-PEI-PAA nanoparticle dispersions, have been adjusted to pH 5, pH 7, and pH 9, respectively. After adsorption and subsequent washing, nanoparticles are characterized by the hydrodynamic radius and the zeta potential, as determined at pH 6. The dependence of

• prepared nanoparticle dispersions were adjusted to pH values between pH 7.4 and pH 0.9 before acquisition of 1H NMR spectra. As a first step, PLGA-PEI(pH 10)-PAA(pH 5)-PDADMAC(pH 9)-PAA(pH 5) nanoparticles were investigated. Alternatively, PLGA-PEI(pH 10)-PAA(pH 5)-PDADMAC(pH 9) nanoparticles have been

Surfactant-controlled composition and crystal structure of manganese(II) sulfide nanocrystals prepared by solvothermal synthesis

• Elena Capetti,
• Anna M. Ferretti,
• Vladimiro Dal Santo and
• Alessandro Ponti

Beilstein J. Nanotechnol. 2015, 6, 2319–2329, doi:10.3762/bjnano.6.238

• centrifugation (three times). The precipitate was finally dispersed in hexane (5–10 mL) by sonication (ultrasonic bath, 1 h, RT). The obtained NC dispersions are stable for several months. Several variants of this procedure were carried out by changing: the manganese precursor (manganese distearate (MnSt2) or

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