The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Anatoly V. Fedorov,
• Kevin Berwick and
• Alexander V. Baranov

Beilstein J. Nanotechnol. 2016, 7, 1018–1027, doi:10.3762/bjnano.7.94

• photophysical properties of the complexes. For the first time this concentration dependence has been well described by the developed model taking into account the heterogeneity of QD–monomer and QD–aggregate complexes. We show that a reduction in the concentration of phthalocyanine aggregates in complex with

• molecules are bound in complexes with QDs, but free QDs can be present in the mixture. Molecules in the complexes can be present as monomers (case (a) in Figure 3) or as non-luminescent aggregates formed by adjoining molecules bound to the QD (cases (b) and (c) in Figure 3). The probability of aggregate

• quenched in complexes with acceptors. The PL quantum yield of monomeric acceptors in the complexes is constant. Molecular aggregates, if present, act as energy acceptors. Here, QDs and monomeric molecules act as energy donors. We propose that complexes containing at least one nonluminescent aggregate do

Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

• Anja Henning-Knechtel,
• Matthew Wiens,
• Mathias Lakatos,
• Andreas Heerwig,
• Frieder Ostermaier,
• Nora Haufe and
• Michael Mertig

Beilstein J. Nanotechnol. 2016, 7, 948–956, doi:10.3762/bjnano.7.87

• irreversibly aggregate during DEP deposition, as it was observed for the formation of conducting wires by DEP deposition of plain, unsupported gold nanoparticles [35][36][37][38][39]. On the other hand, the disassembly of our chain structures upon switching off the electrical field prohibits any further high

• formation of stable nanoparticle wires. We suppose that this is due to two reasons. First, the DNA origami, to which the nanoparticles are attached, keeps them at a distance that does not facilitate direct contact between them to aggregate. TEM imaging revealed a gap size between the gold nanoparticles of

Selective photocatalytic reduction of CO₂ to methanol in CuO-loaded NaTaO₃ nanocubes in isopropanol

• Tianyu Xiang,
• Feng Xin,
• Jingshuai Chen,
• Yuwen Wang,
• Xiaohong Yin and
• Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

• particles were dispersed on the surface of the NaTaO3 nanocubes with an average size of tens of nanometers (Figure 5b and Figure 5c). When the loading reached 5 wt %, the CuO nanoparticles began to aggregate and large clusters were formed (Figure 5d). The UV–vis diffuse reflectance spectra of CuO–NaTaO3 are

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

• media like dissolution, adsorption, binding, and aggregation, all influencing biological impacts by affecting reactive oxygen species generation, cellular uptake and NP biodistribution [15][16][17][18]. Metallic NPs usually aggregate in media with high electrolyte content that correspond to biological

Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates

• Hoai Nga Le,
• Frank Babick,
• Klaus Kühn,
• Minh Tan Nguyen,
• Michael Stintz and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2015, 6, 2423–2430, doi:10.3762/bjnano.6.250

• path of the molecules to be treated. This paper investigates the effect of aggregate size on the photocatalytic activity of pyrogenic titania (Aeroxide® P25, Evonik), which is widely used in fundamental photocatalysis research. Well-defined and reproducible aggregate sizes were achieved by ultrasonic

• . Our results firstly show that a complete dispersion of the P25 aggregates is not practical. Secondly, the photocatalytic activity is not further increased beyond a certain degree of dispersion, which probably corresponds to a critical size for which UV irradiation can penetrate the aggregate without

• from the transmitted light measured with a Varian Cary 100 Bio UV–vis spectrometer [31]. The transmittance was investigated through 10 mm path length P25 suspensions with concentration in the range of 0.01–0.1 g/L and with the aggregate size varying from 234–343 nm. Note that for the second suspension

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

• induces the radiolysis of water. This results in the formation of various radicals (e.g., H•, HO•, e−aq). In the presence of a radical scavenger, H• and e−aq induce reduction of the metal ions into atoms that further aggregate in the solution to form metallic clusters. Usually γ rays or electrons [3] and

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• number-average diameter (TEM) and the hydrodynamic diameter (DLS) is due to the fact that hydrophobic particles tend to aggregate and cannot be resolved as individual particles by DLS. Morphology and crystalline structure of the dry OM–NaYF4:Yb3+/Er3+ nanocrystals were determined by TEM/BF, TEM/ED and

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

• , and a clustered subsystem of nanoparticles. We considered the case of cluster forming because nanoparticles aggregate and form clusters in real-world specimens. Simulated clusters contain 50 nanoparticles with random local distribution. We defined the local volume fraction rV,loc, i.e., the volume

Self-assembly mechanism of Ni nanowires prepared with an external magnetic field

• Xiaoyu Li,
• Hu Wang,
• Kenan Xie,
• Qin Long,
• Xuefei Lai and
• Li Liao

Beilstein J. Nanotechnol. 2015, 6, 2123–2128, doi:10.3762/bjnano.6.217

• diameter of about 95 nm and a length of about 26 μm are composed of spherical-like particles that are connected with each other and form straight chains. Notably, the Ni samples remain chain-like after ultrasonication for 30 min, which implies that the Ni particles grow together and do not simply aggregate

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• brings them to spontaneously segregate in well-defined nanostructures. Therefore, when block copolymers are mixed to solvents which are selective for one of the blocks, polymer chains spontaneously aggregate into micelles having different architectures (i.e., spheres, rods, tubes, lamellae) and degree of

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

• distribution, facile and low cost synthesis process, and ease of surface modification, biological and medical applications using uncoated iron oxide nanoparticles are limited because of their tendency to aggregate and oxidize [9][19]. Covering their surface with organic molecules (e.g., biodegradable polymers

• nanoparticles size measurements, especially in magnetic samples, has been previously reported and could be due to the high tendency of the nanoparticles to aggregate [43][44]. To attempt to overcome this problem, ultrasonic agitation was applied for about 10 min before the measurements. Nevertheless, it seems

How decision analysis can further nanoinformatics

• Matthew E. Bates,
• Sabrina Larkin,
• Jeffrey M. Keisler and
• Igor Linkov

Beilstein J. Nanotechnol. 2015, 6, 1594–1600, doi:10.3762/bjnano.6.162

• , nanoinformatics, determining gaps in the information and risk management technologies, and evaluating opportunities for improvement. These nanoinformatics workshops highlighted a number of resources that were already using nanoinformatics to aggregate and organize nanomaterial data [6]. The Nanoparticle

• literature. Monte Carlo simulations were used to normalize and aggregate individual criteria distributions into distributions of overall performance using criteria weights associated with preferences of different key stakeholders [20]. After developing result distributions that reflect current uncertainties

Using natural language processing techniques to inform research on nanotechnology

• Nastassja A. Lewinski and
• Bridget T. McInnes

Beilstein J. Nanotechnol. 2015, 6, 1439–1449, doi:10.3762/bjnano.6.149

• , nanomedicine, and environmental risk assessment. We believe these approaches can be expanded upon to automatically aggregate studies on the exposure and hazard of ENMs as well as link the physico-chemical properties to the measured effects. Towards this end, we conclude with the following recommendations: Add

The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• injected at the Ni/NiO interface as a consequence of the outward diffusion of Ni are comparable, the vacancies have the ability to migrate toward a position over a long-range distance where they aggregate and form a large single void instead of forming small voids distributed along the Ni/NiO interface

• of Cu, the generated vacancies do not have sufficient mobility to migrate over a long-range distance before they aggregate into one single large void. Rather, they form multiple small voids distributed along the Cu/Cu2O interface (as illustrated in Figure 5e), which leads to an additional step in the

• that the nanodroplet tends to split into multiple tiny dewetting metal bismuth nanodroplets. The droplets then migrate and aggregate on the curved inner surface of the oxide shell before the bismuth wets the surface again (between 410.4 and 413.6 s). They attributed this reversible wetting transition

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• , these Au atoms tend to aggregate into larger particles. The TEM images of the other Au-containing clusters 6 to 8 on MWNT–PPh2 (Figure S2c–e Supporting Information File 1) also show ultrasmall particles with diameters <3 nm and larger particles of different sizes depending on the cluster. For Ru5Au2C(CO

Preparation of Ni/Cu composite nanowires

• Hu Wang,
• Xiaoyu Li,
• Ming Li,
• Kenan Xie and
• Li Liao

Beilstein J. Nanotechnol. 2015, 6, 1268–1271, doi:10.3762/bjnano.6.130

• mechanical stability of Ni/Cu composite nanowires and confirms that they are not merely a loose aggregate of spherical nanoparticles. The EDS graph of the synthesized Ni/Cu composite nanowires in a typical experiment is shown in Figure 1d. The analysis data show that the contents of nickel and copper were

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• current achievements and remaining gaps. Review Colloidal stability and the corona Many NPs are found to aggregate in media that contain electrolytes in high concentrations [74][100][101][102][103]. To prevent NPs from agglomeration upon collision with one another, they are usually stabilized in solution

Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

• Florian Waltz,
• Hans-Christoph Schwarz,
• Andreas M. Schneider,
• Stefanie Eiden and
• Peter Behrens

Beilstein J. Nanotechnol. 2015, 6, 799–808, doi:10.3762/bjnano.6.83

• experiments in which HYA adsorbs onto ZnO crystallites during their growth and thereby influences their size and aspect ratio. Furthermore, those ZnO subunits aggregate under the influence of HYA into highly ordered mesocrystals, which was evidenced by SEM investigations and selected area electron diffraction

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• studied with the HZB-TXM. The electronic states of freestanding CNH aggregate in a dahlia-like shape were investigated and could be related to the presence of pentagonal rings and folding of the graphene sheet in the CNH [66]. Metal impurities due to the exfoliation process of graphite give rise to a pre

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• also their electrical characterization [23]. By contacting a graphitic aggregate with a transition metal tip and passing an electrical current through the junction, carbon chains could be unraveled from the graphitic materials when the tip was retracted (Figure 3). The experiment was carried out under

• graphitic aggregate (top). Both act as electrodes so that the electrical properties of the chain can be measured. Reprinted with permission from [23]. Copyright 2013 American Chemical Society. Measured current–voltage characteristic of a carbon chain (measurements by A. La Torre). A TEM image of the chain

Influence of size, shape and core–shell interface on surface plasmon resonance in Ag and Ag@MgO nanoparticle films deposited on Si/SiO_x

• Sergio D’Addato,
• Daniele Pinotti,
• Maria Chiara Spadaro,
• Guido Paolicelli,
• Vincenzo Grillo,
• Sergio Valeri,
• Luca Pasquali,
• Luca Bergamini and
• Stefano Corni

Beilstein J. Nanotechnol. 2015, 6, 404–413, doi:10.3762/bjnano.6.40

• shift of the plasmon observed at increasing incidence angle, and the presence of a second feature at lower photon energies in the spectra of bare particles, which was assigned to the elongated shapes of the small NP aggregate and the absence of plasmon resonance in SDR at s-polarisation was also

Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents

• Jes Ærøe Hyllested,
• Marta Espina Palanco,
• Nicolai Hagen,
• Klaus Bo Mogensen and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2015, 6, 293–299, doi:10.3762/bjnano.6.27

• oranges and pineapples, scale bar is 100 nm. a) Extinction spectra of solutions of green silver nanoparticles made from orange extract before and after the addition of NaCl, final NaCl concentration was 0.2 M. The inset shows an aggregate formed by green nanoparticles. b) SERS spectrum of pMBA collected

Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes

• Julia M. Tan,
• Jhi Biau Foo,
• Sharida Fakurazi and
• Mohd Zobir Hussein

Beilstein J. Nanotechnol. 2015, 6, 243–253, doi:10.3762/bjnano.6.23

• , and at the same time, further enhance their degree of biocompatibility [7]. This is because non-functionalized CNTs tend to aggregate into bundles due to van der Waals interactions and hence, they might induce apoptosis (cell death) after administration into the human body. Parkinson’s disease (PD) or

Mechanical properties of MDCK II cells exposed to gold nanorods

• Anna Pietuch,
• Bastian Rouven Brückner,
• David Schneider,
• Marco Tarantola,
• Christina Rosman,
• Carsten Sönnichsen and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21

• , blue, *) and ZO-1 (cell borders, green) staining. Arrows indicate the particles (SP: single particle; Ag: aggregate; Cl: cluster, N: nucleus). We refer to clusters as very large aggregates of nanorods. Scale bar: 20 μm. Mechanical analysis of confluent MDCK II cells. Averaged force indentation curves

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• polymer chains aggregate and create voids and channels with walls covered by sulfonic acid functional groups. In the presence of water, protons (H+) detach from the sulfonic acid groups and combine with water molecules to form hydronium complexes (H3O+). To function properly, Nafion needs to be 100