Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• such as antibodies [1][2] and other proteins [3][4]. Aside the specific binding affinity, drug targeting is based on a passive accumulation mechanism that is controlled by particle size and surface characteristics of the colloids. Particles ranging in size between 50 and 300 nm accumulate in solid

• tumors due to the enhanced permeability and retention effect [5]. While circulating through the blood stream, these colloids undergo an opsonization by the immune system followed by endocytosis into macrophages. Particles of greater diameters are rapidly cleared from the plasma and smaller colloidal

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• polymer choice on the size of the resulting nanoparticles was investigated and a mechanism describing their interaction was proposed. It was found that stable colloids of SnO2 nanoparticles are formed in the presence of both PEI and Triton X-100 surfactants as stabilising agents. However, an additional

• the stabilising agent, and temperature. The main feature of colloidal systems in general (not only metal oxide colloids containing nanoparticles) is their tendency to reach the lowest thermodynamic energy state by the agglomeration of nanoparticles. This process usually results in an almost complete

• the case where only a polymeric stabilising agent was used the diameter was 395 nm. Thus, stable colloids of tin dioxide nanoparticles are formed only in solutions containing both stabilising materials (Figure 2). According to literature reports [25], in the first reaction step, PEI creates complexes

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• Laura C. Preiss Katharina Landfester Rafael Munoz-Espi Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany 10.3762/bjnano.5.222 Abstract Biopolymers and biopolymer colloids can act as controlling agents and templates not only in many processes in nature, but also in a

• recent – and in our opinion most representative – synthetic works involving the use of biopolymer and biopolymer colloids for the design of inorganic and inorganic/organic materials, with special emphasis on particles and particle synthesis. In the formation of polymer/inorganic hybrid materials, both

• materials. We propose the following classification, being aware that all divisions are arbitrary to some degree and it may be difficult to place some of the examples in one or other group without ambiguity: A. The use of biopolymers and biopolymer colloids as controlling agents for the precipitation and

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

• /or complex questions, such as the investigation of the agglomeration behavior of colloids under physiological conditions. While addressing questions of such complexity, the necessity for a high level of expertise in light scattering data acquisition, evaluation, and interpretation arises from the

• determination in AF-FFF is not absolute [39]. The mentioned interactions are strongly affected by the concentration and the type of the electrolyte that is added to the eluate. When increasing the salinity of the dispersant, electrostatic repulsions of colloids are reduced by decreasing the Debye screening

• measure for polydispersity. In the third column, the hydrodynamic radii that were obtained for measurements in deionized water are shown. One potential problem of measuring colloids in deionized water was already described above. That is, the inter-particle interactions can cause artifacts in the angular

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• serum for 24 h and a series of aqueous γ-Fe2O3 colloids were added to reach concentrations of 100, 50, 25, 12.5 and 6 µL colloid per mL of fresh cultural medium. The cells were grown with the nanoparticles for 72 h until a confluent monolayer of the cells was obtained. Consequently, 15 μL of MTT dye (5

Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

• Ahmed Salama,
• Mike Neumann,
• Christina Günter and
• Andreas Taubert

Beilstein J. Nanotechnol. 2014, 5, 1553–1568, doi:10.3762/bjnano.5.167

• instrument is 0.3%. Acknowledgements We thank Ms. C. Pilz-Allen (funded by the Biomaterials Department, MPI of Colloids and Interfaces) for generously supporting us with the cell culture experiments. We thank the University of Potsdam for financial support. A.S. acknowledges a Channel Fellowship awarded by

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

• Christoph Rehbock,
• Jurij Jakobi,
• Lisa Gamrad,
• Selina van der Meer,
• Daniela Tiedemann,
• Ulrike Taylor,
• Wilfried Kues,
• Detlef Rath and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

• these effects are anion specific and do not occur in the presence of hard anions like F− which destabilizes gold colloids even at low salinities. This size quenching effect has been attributed to the adsorption of anions to primary particles during particle formation, which electrostatically stabilizes

• stability will increase upon dilution. Based on the above mentioned three determining factors it may be concluded that ligand-free colloids may only be used as primary particles in biological assays when they are highly diluted, while at higher concentrations mainly aggregates have to be considered. However

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

• Claudio Davet Gutiérrez-Lazos,
• Mauricio Ortega-López,
• Manuel A. Pérez-Guzmán,
• A. Mauricio Espinoza-Rivas,
• Francisco Solís-Pomar,
• Rebeca Ortega-Amaya,
• L. Gerardo Silva-Vidaurri,
• Virginia C. Castro-Peña and
• Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2014, 5, 881–886, doi:10.3762/bjnano.5.100

• and Discussion TEM analysis In general, well crystallized CdTe colloids were obtained, as shown in Figure 1b. We were unable to assess the size and shape of the samples. Although the absorbance spectrum displays a sharp excitonic peak indicating a nearly monodispersed nature of our samples, the degree

• glass substrates (see Figure 2). As mentioned above, XRD and Raman measurements corroborated the phase composition of the colloids. Figure 3 shows the X-ray diffraction patterns of deposited CdTe-NC at concentrations of 2.24 and 0.45 mmol trioctylphosphine (TOP), respectively. The diffraction patterns

• lower than 2.4 mmol, impurity-free CdTe colloids were obtained. Optical characterization According to Figure 2, our CdTe colloids display a strong red luminescence, indicating quantum confinement in the nanosized CdTe crystals. It is known that quantum confinement can be observed for crystallite sizes

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• of particles with the diameter Di) documents a moderately broad particle size distribution (Table 1). The obtained iron oxide nanoparticle colloids were also investigated by dynamic light scattering (DLS). The hydrodynamic diameter (Dh) of the nanoparticles calculated from DLS was about 10 times

Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development

• Ulrike Taylor,
• Wiebke Garrels,
• Annette Barchanski,
• Svea Peterson,
• Laszlo Sajti,
• Andrea Lucas-Hahn,
• Lisa Gamrad,
• Ulrich Baulain,
• Sabine Klein,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2014, 5, 677–688, doi:10.3762/bjnano.5.80

• in water, which generates colloidal particles of maximal purity [43][44][45]. Without compromising this purity, monomodal and monodisperse gold colloids can easily be fabricated in micromolar saline water with defined AuNP sizes [46]. Alternatively, this method also provides particles displaying a

• µg/mL] AgNP dispersion was added to a blastomere with a volume of 90 pL [56]. The chosen concentration of Ag+-ions was approximated based on previously reported ion release kinetics of silver colloids in aqueous solution [57]. Control co-incubations of embryos with equimolar KNO3 showed no effect

• can unfold toxic properties of their own [78]. The studies performed on avian embryos and the experiments presented here employed particles synthesized by physical means, an electric non-explosive method and laser ablation in water, respectively. Those methods produce colloids completely free of any

Cyclic photochemical re-growth of gold nanoparticles: Overcoming the mask-erosion limit during reactive ion etching on the nanoscale

• Burcin Özdemir,
• Axel Seidenstücker,
• Alfred Plettl and
• Paul Ziemann

Beilstein J. Nanotechnol. 2013, 4, 886–894, doi:10.3762/bjnano.4.100

• distance within a given periodic arrangement. 5) The maximizing of defect-free domain sizes of such NP lattices. A relative simple and affordable approach that nevertheless addresses all the above requirements is based on the self-organization of organic carrier systems such as colloids or reverse micelles

Grain boundaries and coincidence site lattices in the corneal nanonipple structure of the Mourning Cloak butterfly

• Ken C. Lee and
• Uwe Erb

Beilstein J. Nanotechnol. 2013, 4, 292–299, doi:10.3762/bjnano.4.32

• [25][26][27] have been found in numerous studies. Rows of 5–7–7–5 defects and other combinations have also been associated with grain boundaries in such structures [27]. Coordination defects are also common in other curved surfaces with closest packed structures such as polymer colloids assembled on

Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

• Alexander Weddemann,
• Judith Meyer,
• Anna Regtmeier,
• Irina Janzen,
• Dieter Akemeier and
• Andreas Hütten

Beilstein J. Nanotechnol. 2013, 4, 164–172, doi:10.3762/bjnano.4.16

• a situation similar to Figure 1. However, this observation does not exclude a deformation along the out-of-plane direction such as the flattening of the spheres towards ellipsoidal colloids. For the imaging of a particle cross section along the out-of-plane axis, a thin sample lamella was prepared

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• -beam lithography, nanoperforated templates, polymer structures, or colloids, to name a few [15][16][17][18]. In the present contribution we have chosen a platform that allows the variation of the relevant parameters such as nanostructure size and their mutual distance, which are not easily accessible

• by the approaches mentioned above. The technique is based on self-assembly and homogeneous size reduction of polystyrene (PS) colloids [19] ending up with a non-close-packed monolayer of colloidal particles, which, in turn, serves as a template for the subsequent deposition of magnetic films. In the

• nanostructure by choice of (commercially available) colloids and the adjustment of the remaining diameter by total etching time, respectively. Figure 2 presents a scheme illustrating the method for one initial diameter and three final sizes of PS spheres at constant distance achieved after different plasma

Growth behaviour and mechanical properties of PLL/HA multilayer films studied by AFM

• Cagri Üzüm,
• Johannes Hellwig,
• Narayanan Madaboosi,
• Dmitry Volodkin and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2012, 3, 778–788, doi:10.3762/bjnano.3.87

• Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany 10.3762/bjnano.3.87 Abstract Scanning- and colloidal-probe atomic force microscopy were used to study the mechanical properties of poly(L-lysine)/hyaluronan (PLL/HA)n films as a function of indentation velocity and the

Controlled positioning of nanoparticles on a micrometer scale

• Fabian Enderle,
• Oliver Dubbers,
• Alfred Plettl and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 773–777, doi:10.3762/bjnano.3.86

• them as masks for subsequent etching procedures to transfer the NP pattern into their supporting substrate. In this respect, the notion of a nanoparticle should include as well colloids and micelles since their use for patterning is more widely spread [7][8][9][10][11][12]. Of course, in addition to

• been successfully demonstrated. Though related to two-dimensional non-close-packed colloidal crystals [11] and, thus, primarily leading to the formation of hexagonal arrays of NPs, the method is novel in that it applies colloids carrying metal precursors. Once the colloidal carriers form a self

• sufficient for the just mentioned applications, further improvements appear possible. A necessary prerequisite for this would be a better long-range order of the starting NPs. For this, changing to self-assembled precursor-loaded colloids rather than micelles is promising [10][11][12]. In the ideal case

Assessing the plasmonics of gold nano-triangles with higher order laser modes

• Laura E. Hennemann,
• Andreas Kolloch,
• Andreas Kern,
• Josip Mihaljevic,
• Johannes Boneberg,
• Paul Leiderer,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2012, 3, 674–683, doi:10.3762/bjnano.3.77

• piece of either silicon (commercial silicon wafer) or glass (commercial glass slide by Menzel-Gläser). A thin gold film was then evaporated with the polystyrene colloids acting as a mask on the substrate. Finally, the colloids were removed with a piece of adhesive tape. The resulting sample is a regular

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• hydrogen-terminated Si surface. Au colloids (80 nm) in propan-2-ol were then dropped onto the substrate and after evaporation of the solvent and an additional dip in BHF, the samples were immediately introduced into the APCVD system. The reactor was evacuated and purged with He, three times, to remove any

• electron beam lithography, Ni sputter deposition and lift-off techniques. Results and Discussion Single-crystalline and epitaxial Si-NWs were grown by using OCTS as a precursor and Au colloids at a growth temperature of 700 °C, with a pre-annealing of the samples at 800 °C for 30 min. The thus synthesized

• . Again effective NW growth required the addition of H2 to the growth atmosphere and a higher growth temperature of at least 800 °C. Furthermore, to achieve epitaxial NW growth, the colloids were replaced by a 2 nm thick sputter-deposited Au layer. Epitaxial NWs about 60 nm to 150 nm in diameter and up to

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• Sergiu Amarie Paul Zaslansky Yusuke Kajihara Erika Griesshaber Wolfgang W. Schmahl Fritz Keilmann Max Planck Institute of Quantum Optics and Center for NanoScience, 85748 Garching, Germany Max Planck Institute of Colloids and Interfaces, Wissenschaftspark Golm, 14424 Potsdam, Germany Department of

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• selected photocatalysts. Supporting Information Supporting Information File 20: Additional Figures. Acknowledgements J.-M. Wu appreciates the research fellowship awarded by the Alexander von Humboldt Foundation. Prof. Antonietti and MPI of Colloids and Interfaces are thanked for hosting J.-M. Wu and for

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• the ZnO/Au photoelectrode was compared with the absorption by Au nanoparticle colloids (particle size ~20 nm), and the results indicated that the Au nanoparticles in both systems were of comparable sizes, which was further verified by TEM imaging. A typical TEM image of the ZnO/Au-nanorod surface is

• of Au nanoparticle colloids as described by Sugunan et al. [40]. A diluted 0.01 mM aqueous solution of gold chloride hydrate (HAuCl4·H2O, Aldrich) was prepared by adding 1 mL of 5 mM HAuCl4·H2O aqueous solution to 50 mL of DI water. The solution was then stirred for 15 min to mix the solute properly

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

• Lars Borchardt,
• Martin Oschatz,
• Robert Frind,
• Emanuel Kockrick,
• Martin R. Lohe,
• Christoph P. Hauser,
• Clemens K. Weiss,
• Katharina Landfester,
• Bernd Büchner and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 638–644, doi:10.3762/bjnano.2.67

• of nonionic Lutensol AT50 results in larger spheres of 500 nm (Figure 2A). This is not surprising, as nonionic surfactants are less effective in stabilizing colloids. Thus a larger amount of nonionic surfactant is required to achieve the same particle size as with an ionic surfactant. The variation

Fabrication of multi-parametric platforms based on nanocone arrays for determination of cellular response

• Lindarti Purwaningsih,
• Tobias Schoen,
• Tobias Wolfram,
• Claudia Pacholski and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2011, 2, 545–551, doi:10.3762/bjnano.2.58

• autocatalytic process that allows for the spatially resolved deposition of metal on to metal surfaces or colloids. Gold nanoparticle arrays with gold particle diameters of approximately 30–45 nm were prepared (Figure S1b). Finally, a reactive ion etching (RIE) process was employed to generate nanocone arrays

Nanoscaled alloy formation from self-assembled elemental Co nanoparticles on top of Pt films

• Luyang Han,
• Ulf Wiedwald,
• Johannes Biskupek,
• Kai Fauth,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 473–485, doi:10.3762/bjnano.2.51

• probe microscopy techniques [5], one is left with processes relying on the self-assembly of colloids or micelles [6][7][8]. In the context of magnetic NPs, two prominent examples, both dealing with the preparation of magnetically attractive FePt NPs, which successfully demonstrated fulfillment of the

Platinum nanoparticles from size adjusted functional colloidal particles generated by a seeded emulsion polymerization process

• Nicolas Vogel,
• Ulrich Ziener,
• Achim Manzke,
• Alfred Plettl,
• Paul Ziemann,
• Johannes Biskupek,
• Clemens K. Weiss and
• Katharina Landfester

Beilstein J. Nanotechnol. 2011, 2, 459–472, doi:10.3762/bjnano.2.50

• -assembled monolayer of functional colloids is prepared on a solid substrate and subsequently treated by oxygen plasma processing in order to remove the organic constituents. This step, however, leads to a saturated state of a residual mix of materials. In order to determine parameters influencing this

• saturation state, the type of surfactant, the amount of precursor loading and the size of the colloids are varied. By short annealing at high temperatures platinum nanoparticles are generated from the saturated state particles. Typically, the present fabrication method delivers a maximum interparticle

• distance of about 260 nm for well-defined crystalline platinum nanoparticles limited by deformation processes due to softening of the organic material during the plasma applications. Keywords: colloid lithography; functional colloids; miniemulsion polymerization; nanoparticles; seeded emulsion