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

• by sodium hypochlorite and the coating with D-mannose and poly(N,N-dimethylacrylamide) according to earlier reports [20][25]. While coating with D-mannose was performed by the slow addition of D-mannose solution to the γ-Fe2O3 colloid, coating with PDMAAm included solution radical polymerization of N

• 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

• control and all of them revealed cytotoxic activity. At the same time, the data confirmed the tendency of decreasing particle cytotoxicity if coated with PDMAAm or D-mannose. The strongest cytotoxic effect was observed at the highest concentration of the colloid (100 µL/mL of medium). The PDMAAm-coated γ

Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

• Priscilla Vasthi Quintana-Ramirez,
• Ma. Concepción Arenas-Arrocena,
• José Santos-Cruz,
• Marina Vega-González,
• Omar Martínez-Alvarez,
• Víctor Manuel Castaño-Meneses,
• Laura Susana Acosta-Torres and
• Javier de la Fuente-Hernández

Beilstein J. Nanotechnol. 2014, 5, 1542–1552, doi:10.3762/bjnano.5.166

• cells. Experimental Crystalline copper sulfide nanostructures were obtained by one-pot synthesis in an organic solvent while raising the reaction temperature from 220 to 260 °C. Amorphous copper sulfide was also synthesized by a chemical reaction in aqueous solution at 40 °C. Films, colloid and powder

Near-field photochemical and radiation-induced chemical fabrication of nanopatterns of a self-assembled silane monolayer

• Ulrich C. Fischer,
• Carsten Hentschel,
• Florian Fontein,
• Linda Stegemann,
• Christiane Hoeppener,
• Harald Fuchs and
• Stefanie Hoeppener

Beilstein J. Nanotechnol. 2014, 5, 1441–1449, doi:10.3762/bjnano.5.156

• highly localized shadow. The removal of the gold mask reveals the SAM nanopattern. Keywords: colloid lithography; contact lithography; near-field; photochemistry; self-assembled silane monolayers; Introduction Chemical nanopatterns consist of spatially separated areas providing different chemically

Surface processes during purification of InP quantum dots

• Natalia Mordvinova,
• Pavel Emelin,
• Alexander Vinokurov,
• Sergey Dorofeev,
• Artem Abakumov and
• Tatiana Kuznetsova

Beilstein J. Nanotechnol. 2014, 5, 1220–1225, doi:10.3762/bjnano.5.135

• from byproducts. There are a lot of strategies for the size and shape-selective purification of nanoparticles [7]. Size-selective precipitation is one of the most important separation technique used widely in colloid chemistry. It relies on the fractional precipitation from a “good” solvent by addition

Nanodiamond-DGEA peptide conjugates for enhanced delivery of doxorubicin to prostate cancer

• Amanee D Salaam,
• Patrick Hwang,
• Roberus McIntosh,
• Hadiyah N Green,
• Ho-Wook Jun and
• Derrick Dean

Beilstein J. Nanotechnol. 2014, 5, 937–945, doi:10.3762/bjnano.5.107

• shown in Scheme 1. With this technique, EDAC was used to activate carboxylic groups on the ND surface. Sulfo-NHS was used to form a stable amide bond between the –COOH groups on the NDs and the free NH2 groups on DGEA. Briefly, 200 µL of ND colloid (5 mg/mL in distilled water) was added with 100 µL of

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

• distribution for our samples. Nevertheless the exciton peak disappeared once the CdTe colloid was drop-cast on the glass substrates Figure 5 shows the absorbance spectra of CdTe-NC of the colloidal solution and of a liquid sample processed by the size-separation technique. The effect of size-separation can be

• observed by considering the maximum absorption peak. The excitonic peak is narrower than that the of the colloid and nearly symmetric, similar to a nearly monodispersed sample. Additionally, the maximum absorbance has shifted from 607 nm to 589 nm arguing for a lower size dispersion of the CdTe-NC. However

• , this result imposes a technological limitation in the colloid application in a thin-film device due to strong stabilization of oleic acid, which is nonconductive and separates the nanocrystals with spacings of about 0.7 nm and thus impedes their electrical contact [15]. Conclusion Oleic acid-stabilized

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

• , 0.1 M sodium citrate (13 mL) was added under sonication, and the magnetite was oxidized by slow addition of 5% sodium hypochlorite solution (10 mL) to yield maghemite (γ-Fe2O3). The above described washing procedure was repeated with the resulting primary colloid, which was finally passed through a

• Millex HV syringe filter (0.45 µm membrane, 33 mm in diameter). Coating of colloidal iron oxide nanoparticles was achieved by the post-synthesis method [12]. Aqueous D-mannose (2 mL; concentration 128 mg/mL) was added dropwise under sonication to a portion of primary colloid containing 44 mg of iron

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• are observed. The above results demonstrate that high concentration of TGA is not favourable for the formation of monodisperse CZTS nanocrystals. At a high concentration, TGA might form a colloid which wraps a certain surface of CZTS particles, inhibiting the growth of crystals in all directions [25

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• instance, a nano-colloid has been synthesized using a top-down wet chemistry method with bulk ZnO powder with grain size of 1–2 mm as starting material [9]. Stearic or oleic acids have been used as capping agents in the stabilization technique to prevent agglomeration of the ZnO nanoparticles [9][10][11

Photoactivation of luminescence in CdS nanocrystals

• Valentyn Smyntyna,
• Bogdan Semenenko,
• Valentyna Skobeeva and
• Nikolay Malushin

Beilstein J. Nanotechnol. 2014, 5, 355–359, doi:10.3762/bjnano.5.40

• cadmium sulfide nanocrystals (NCs) synthesized by colloid chemistry in a gelatinous matrix. The photostimulation of the short-wavelength emission band with λmax = 480 nm has been detected. It is shown that the determining factor of the photostimulation effect is the adsorption of the water molecules on

• nanocrystals used in these experiments were prepared by colloid chemistry of solutions of cadmium- and sulfursalts in an aqueous gelatin solution. Details of the sample preparation are described in [15]. The average radius of the cadmium sulfide nanocrystals was calculated from the optical absorption spectra

Design criteria for stable Pt/C fuel cell catalysts

• Josef C. Meier,
• Carolina Galeano,
• Ioannis Katsounaros,
• Jonathon Witte,
• Hans J. Bongard,
• Angel A. Topalov,
• Claudio Baldizzone,
• Stefano Mezzavilla,
• Ferdi Schüth and
• Karl J. J. Mayrhofer

Beilstein J. Nanotechnol. 2014, 5, 44–67, doi:10.3762/bjnano.5.5

• ], nanohorns [29], ordered mesoporous carbons (OMCs) [30][31], carbon aerogels [32], carbon shells [33][34][35][36], colloid-imprinted carbon supports (CIC) [37] and even boron-doped diamond structures [38][39]. Alternatively, certain non-carbon materials (e.g., oxides, carbides and nitrides of metals such as

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• glass substrates were initially cleaned by successive sonication in soap water, acetone, ethanol and DI water respectively for 15 min each. Once the solvent on the glass substrates dried, another 100 μL of the ZnO nanoparticle colloid was dropped again and the process was repeated several times. A total

• of 10 mL ZnO nanoparticle colloid was dropped on each glass substrate. Finally, the ZnO nanoparticle coated glass substrates were annealed at different temperatures up to 350 °C in air for 1 h. The annealed ZnO nanoparticles were then redispersed in chloroform by sonication for 1 h and stored in dark

Ultramicrosensors based on transition metal hexacyanoferrates for scanning electrochemical microscopy

• Maria A. Komkova,
• Angelika Holzinger,
• Andreas Hartmann,
• Alexei R. Khokhlov,
• Christine Kranz,
• Arkady A. Karyakin and
• Oleg G. Voronin

Beilstein J. Nanotechnol. 2013, 4, 649–654, doi:10.3762/bjnano.4.72

• [18]. The electrodeposition of nickel hexacyanoferrate (NiHCF) was carried out in a non-colloid solution containing 1 mM NiCl2 and 0.5 mM K3[Fe(CN)6] with an excessive amount of supporting electrolyte (0.1 M HCl and 0.5 M KCl), while cycling the electrode potential between 0 and 0.85 V at a scan rate

Mapping of plasmonic resonances in nanotriangles

• Simon Dickreuter,
• Julia Gleixner,
• Andreas Kolloch,
• Johannes Boneberg,
• Elke Scheer and
• Paul Leiderer

Beilstein J. Nanotechnol. 2013, 4, 588–602, doi:10.3762/bjnano.4.66

• these data to Equation 3 the detailed fluence profile can be derived. (Such a fit is shown in Figure S1 in Supporting Information File 1.) Sample preparation For the preparation of the plasmonic structures two kinds of nanostructuring methods have been applied, namely colloid lithography and electron

• beam lithography. The material used was exclusively gold. Figure 3a and Figure 3b present an example for the first and Figure 3c and Figure 3d for the second technique, respectively. In colloid lithography, self-assembled monolayers of meso- or nanoscopic spherical particles are produced by self

• of colloid lithography is that, while it is relatively easy to implement, periodic arrays of uniform nanostructures can be distributed over large areas (up to a few cm2). Furthermore, the triangular structures prepared with this method can have tip radii as small as 5 nm, a size which is difficult to

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Balati Kuerbanjiang,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• the CVR process. Future work will therefore aim at an integration of the ALD process into the CVR technique. B. Systems with Ag nanoantennas from NSL Nanosphere lithography (NSL) is a well-established technique for the generation of periodic structures on the submicron scale [17]. Colloid spheres

• as template masks for deposition of materials through the open holes of the layer structure. After removal of the colloid particles, typically arrangements of triangular structures are obtained. The distance between the structures is determined by the size of the original colloid sphere, and can be

• gap between the antennas. Since the structural dimension and the gap size scale with the diameter of the colloid spheres, the use of smaller spheres is more promising. However, for very small sphere sizes it gets increasingly difficult to identify the positions of individual antennas in the confocal

Sub-10 nm colloidal lithography for circuit-integrated spin-photo-electronic devices

• Adrian Iovan,
• Marco Fischer,
• Roberto Lo Conte and
• Vladislav Korenivski

Beilstein J. Nanotechnol. 2012, 3, 884–892, doi:10.3762/bjnano.3.98

• complexity, efficiency, areal scale, and cost. Colloid-based patterning is known to be capable of producing individual sub-10 nm objects. However, ordered, large-area nano-arrays, fully integrated into photonic or electronic devices have remained a challenging task. In this work, we extend the practice of

• fabrication tool in bio-, opto-, and nanotechnology. Nanoparticles in the colloid are made to form a mask on a given material surface, which can then be transferred by etching into nanostructures of various sizes, shapes, and patterns [2][3]. Such nanostructures can be used in biology for detecting proteins

• ease of use and low cost. Colloid-based patterning is known to be capable of producing individual sub-10 nm objects. However, ordered large-area nano-arrays fully integrated into photonic or electronic devices have not been demonstrated by using colloidal lithography. In this work we use a self

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

• , respectively. Alternatively to film deposition on size-reduced PS particles for percolated magnetic films, one may use self-assembly of inorganic spheres, such as Au nanoparticles, for nanostructuring. Commercially available Au colloid solutions with particle sizes of 60 and 40 nm have been used to prepare

• monolayers of self-assembled Au particles on thermally oxidized Si(100) substrates [28]. The Au colloid solution was diluted with pure ethanol in the volume ratio of 2:1. A volume of 60 µL of such solution was dispersed onto the substrates and dried under ambient conditions in a covered box to prevent air

• flow (see [29] for details). The arrangement of the nanoparticles in the islands was investigated by SEM. Due to the low particle concentration in the colloid solution they form a number of irregularly shaped islands, which extend over several tens of microns. Figure 4 presents two SEM micrographs of

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

• , positioning of the resist disks would no longer be purely statistical but instead conform to multiples of the lattice parameter of the underlying hexagonal colloid lattice. To exploit the high long-range colloidal order, however, a sample holder with laser-interference-controlled translations becomes a must

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

• -triangles in particular [3][4][5][6] has been investigated both directly and indirectly. Likewise, the plasmonic behaviour of metallic nano-triangle arrays, namely Fischer patterns [7] made by colloid lithography, has been studied to some extent. Optical extinction spectroscopy [8], confocal microscopy [9

• either onto an avalanche photodiode (APD) or onto a grating spectrometer coupled with a liquid nitrogen cooled CCD camera. The samples were prepared by colloid lithography. Via drying of a strongly diluted colloidal suspension, a self-assembled monolayer of polystyrene spheres was created on a substrate

Colloidal lithography for fabricating patterned polymer-brush microstructures

• Tao Chen,
• Debby P. Chang,
• Rainer Jordan and
• Stefan Zauscher

Beilstein J. Nanotechnol. 2012, 3, 397–403, doi:10.3762/bjnano.3.46

• evaporation of solvents [1][2][3][4]. Such periodic arrays of microspheres were used already in the early 1980s by Fischer and co-workers as shadow masks in colloid lithography (CL) for the deposition of platinum nanomaterials [5]. Since then, CL has become a simple, versatile, and cost-effective fabrication

• technique for a large number of researchers in the field of micro/nanofabrication [2][3][4][6]. A variety of lithographic methods have since been developed, in which colloid microsphere arrays are used as masks for depositing nanomaterials and as scaffolds for templating 2-D or 3-D functional patterns [2][3

• nanoscale, by changing the sphere diameter of the colloid mask. Spherical particles are commercially available with a wide range of sizes and types, or can be synthesized, e.g., by emulsion polymerization for polymer latex spheres or by controlled precipitation for inorganic oxides [12]. Patterned polymer

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• determined by transmission electron microscope (TEM, JEOL-2100) with an accelerating voltage of 200 kV. For TEM experiments, the specimens were prepared by deposition of a dilute solution of the colloid onto a carbon-coated copper grid and drying at room temperature. Thermogravimetric (TG) measurements were

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• two-steps method, in which a HS–(CH2)10–COOH monolayer was first adsorbed on gold and then exposed to an ethanolic TiO2 colloid solution, and a one-step process in which an ethanolic colloid of TiO2 nanocrystallites was prepared by the sol–gel method in the presence of the functionalized thiols prior

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

• 0.01 mM HAuCl4·H2O aq. solution. (a) Optical absorption of ZnO nanorods, ZnO/Au-nanocomposite photoelectrode and Au-nanoparticle colloid (particle size ~20 nm) and (b) TEM image of Au nanoparticles in situ deposited on the surface of a ZnO nanorod. (a) J–V characteristics of the bare ZnO-nanorod and

Distinction of nucleobases – a tip-enhanced Raman approach

• Regina Treffer,
• Xiumei Lin,
• Elena Bailo,
• Tanja Deckert-Gaudig and
• Volker Deckert

Beilstein J. Nanotechnol. 2011, 2, 628–637, doi:10.3762/bjnano.2.66

• stranded calf thymus DNA (Sigma-Aldrich) were used in these experiments without further purification. Any further chemicals used for buffer solutions and colloid synthesis were purchased either at Sigma-Aldrich or VWR international. The adenine homopolymer and the calf thymus DNA were dissolved in a buffer

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

• 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

• the reaction details, respectively. First, sodium chloride was added to the continuous phase. The presence of salt affects the stability of colloidal particles as the extension of the electrical double layer of ionic surfactants present at the colloid interface is reduced by the counter ions of the

• of the colloid and its value in the saturated state after etching, one arrives at an equivalent Pt layer thickness of around 3 to 4 Å (Pt lattice parameter aPt = 3.92 Å). A similar result was obtained for Pt-precursor loaded polymethylmethacrylate (PMMA) particles [35]. This suggests that the