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

• , noble metals such as gold, or oxide layers such as silica or alumina) not only prevents their aggregation due to the change in surface charge, but also protects them from oxidation [12][20][21]. Additionally, proper surface coverage increases the stability and half-life of the magnetic nanoparticles

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• the limit of zero surface coverage), and Θ is the adsorbate coverage, i.e., the fraction of surface sites occupied by physisorbed gas molecules: where Aa is the area of a surface site occupied by adsorbate ‘a’, and 1/Aa is the maximum possible concentration of species ‘a’. We note that Equation 2

• describes non-activated Langmuir adsorption of a single molecular species ‘a’. The Langmuir model limits the surface coverage to one monolayer (hence the term (1 − Θ) in Equation 2), and can be modified to account for other adsorption behavior such as multilayer adsorption and thermally activated

• model, i.e., the time at which the gas pressure is changed from 0 to Pa. A typical time-evolution of Na in the absence of electron irradiation is shown in Figure 3. As t → ∞, the surface coverage reaches a steady-state equilibrium value, , which is the initial value that is input into FEBIP models (in

Nanomechanical humidity detection through porous alumina cantilevers

• Olga Boytsova,
• Alexey Klimenko,
• Vasiliy Lebedev,
• Alexey Lukashin and
• Andrey Eliseev

Beilstein J. Nanotechnol. 2015, 6, 1332–1337, doi:10.3762/bjnano.6.137

• increase of the experimental water surface coverage of about 8% within the experimental humidity levels. From the Langmuir sorption isotherm a humidity change from 10 to 22% should result in growth of the surface coverage by 8.9%, which fits well to the obtained value. However, despite the good agreement

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• area per molecule isotherms and Brewster angle microscopy images indicate that 1 forms true monolayers at the air–water interface. LB films of 1 were fabricated by deposition of the Langmuir films onto solid supports resulting in monolayers with surface coverage of 0.98 × 10−9 mol·cm−2. The morphology

• microbalance (QCM). The frequency change (Δƒ) for a QCM quartz resonator before and after the deposition process was experimentally determined. This frequency change can be introduced in the Sauerbrey equation [95]: to determine the surface coverage. In Equation 1, f0 is the fundamental resonance frequency of

• 5 MHz, Δm(g) is the mass change, A is the electrode area, ρq is the density of the quartz (2.65 g·cm-3), μq is the shear modulus (2.95 × 1011 dyn·cm−2), and the molecular weight of 1 is 280 g·mol−1. Thus, the surface coverage of 1 incorporated into LB films, obtained from Equation 1, is 0.98 × 10−9

Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

• Brett B. Lewis,
• Michael G. Stanford,
• Jason D. Fowlkes,
• Kevin Lester,
• Harald Plank and
• Philip D. Rack

Beilstein J. Nanotechnol. 2015, 6, 907–918, doi:10.3762/bjnano.6.94

• surface coverage. Beam parameter studies To explore this growth mechanism further we performed two additional studies: 1) increased pixel spacing on the live scan imaging during purification by a factor of 1.85, and 2) reduced the current to about 0.5 nA (ca. 3.6× reduction). Figure 3a compares the

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

• enough proteins were present in solution to cover all NP surfaces in a monolayer fashion. By introducing a new model, based on statistical considerations of the collision geometries, they showed that a plot of the surface coverage versus the logarithmic protein concentration indeed resembled a binding

• change the nature of protein adsorption onto their NPs (Figure 4). The adsorption of native HSA led to a radius increase due to protein adsorption of Δrh = (3.3 ± 0.6) nm, commensurate with a complete surface coverage by HSA molecules adsorbing with their triangular faces to the QDs and well in line with

• eye. The collision efficiency becomes zero around the point where monolayer surface coverage can be expected. (b): Data-plot of surface coverage versus the logarithmic HSA-concentration from the same study [53]. Surface coverage was inferred from the stabilizing effect of the HSA corona forming around

Stick–slip behaviour on Au(111) with adsorption of copper and sulfate

• Nikolay Podgaynyy,
• Sabine Wezisla,
• Christoph Molls,
• Shahid Iqbal and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2015, 6, 820–830, doi:10.3762/bjnano.6.85

• . This potential corresponds to the peak in the cyclic voltammogram which is due to formation of the copper 2/3 layer. At this peak potential, copper makes up about 30% surface coverage. In our previous experiments, such a large friction value was observed when stepping the potential from a potential of

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• deposition or bulk segregation in UHV [1][5]. These are typically up to tens of nanometers long and spaced about three times the periodicity of the substrate in the perpendicular direction. Depending on the surface coverage, these Ca-related, linear features also show different spacings of two, four, or

• for adsorption [6]. Interestingly, San Miguel et al. [6] report that from increasing the surface coverage of the surface as well as reducing the proximity to an oxygen vacancy, a significant reduction of the adsorption energy for Ca results. This means that calcium dissolution from the TiO2 surface

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• involves the surface coverage, θ, the adsorption energy, Eads, and the area per surface atom, Aat [15]: Interactions between adsorbates are implicitly taken into account in Equation 1, as these interactions will affect the values of both Eads and θ. An example of Wulff construction is shown in Figure 1 for

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

• measured surface coverage of phosphoric acid on platinum as a function of the cell potential is very different from what was observed in [63]. Similar to the FTIR measurements from Iwasita et al. [60], they observed an increase of phosphoric acid adsorption starting from 0 mV. The maximum coverage in their

Formation of stable Si–O–C submonolayers on hydrogen-terminated silicon(111) under low-temperature conditions

• Yit Lung Khung,
• Siti Hawa Ngalim,
• Andrea Scaccabarozzi and
• Dario Narducci

Beilstein J. Nanotechnol. 2015, 6, 19–26, doi:10.3762/bjnano.6.3

• observation would further reinforce hydrogen abstraction as a viable mechanism for low temperature hydrosilylation. It is important to note that the film produced on the silicon surface can only described as a sub-monolayer as attaining a full surface coverage in which every silicon atom is occupied would be

Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

• Christina Rosman,
• Sebastien Pierrat,
• Marco Tarantola,
• David Schneider,
• Eva Sunnick,
• Andreas Janshoff and
• Carsten Sönnichsen

Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257

• decorated with various amounts of surfactant-coated particles. A surface density of 65 particles/µm2 (which corresponds to 0.5% of surface coverage with nanoparticles) diminishes micromotion by 25% as compared to bare substrates after 35 hours of incubation. We conclude that the surface coating of the gold

• spreading area at day two. This example is chosen as a representative of the average behavior in increase of the surface coverage with individual cells showing a smaller or even larger expansion compared to the presented cell. Adherence The adherence of cells was indicated by the amount of adherent cells

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

• error in this estimate is probably due to changes in the molar extinction coefficient upon anchoring at the surface (Figure 3 (left) shows two maxima with different absorbance where free MPD has the same). Since the surface coverage is low, we expected that the labelling would not interfere with

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• signature of thiophenol-functionalized gold nanoparticles (17 nm of diameter) grafted on flat silicon could be detected at a surface coverage as low as about 1% [70][71]. The SFG spectra displayed a single mode corresponding to the CH groups of the aromatic core of thiophenol at 3055 cm−1 (Figure 6). The Au

• NPs surface coverage on a prefunctionalized aminopropyl-triethoxysilane (APTES) silicon substrate could be varied from 1.5% (5 min) to 15% (24 h) depending on the dipping time in the colloidal solution (Figure 6). When comparing the SFG signal of the thiophenol molecules chemisorbed on the NPs

• substrate (15% of surface coverage) with the same thiophenol SAM (self-assembled monolayer) chemisorbed on a Au(111) monocrystal, the normalized intensity enhancement was estimated to be 21. Actually, a 1.5% NPs surface coverage already led to a significant SFG vibrational signature, which underlines the

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• (see distributions in Figure 5) [31]. The effect originates in the difference of surface coverage by the R6G dried film and by the Au nanoparticles. The latter is low and does not exceed 30%, while the dye film covers the entire nanoarray surface together with the inter-particle areas. In consequence

Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles – a fluorescence correlation spectroscopy study

• Pauline Maffre,
• Stefan Brandholt,
• Karin Nienhaus,
• Li Shang,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2036–2047, doi:10.3762/bjnano.5.212

• of a perhaps incomplete QD coating during protein adsorption. The complete reversibility of the corona formation on DHLA–QDs (see below) suggests that protein denaturation does not occur. A problem with incomplete surface coverage with DHLA is also highly unlikely in view of the negative zeta

• with (red) HSA at concentrations ensuring complete surface coverage ((a) 800 µM, (b) 40 µM HSA). Symbols: data, lines: fits. Hydrodynamic radii, RH, of differently functionalized CdSe/ZnS QDs as a function of the concentration of proteins freely diffusing in solution. Details of the NPs and proteins

In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

• Wolfgang G. Kreyling,
• Stefanie Fertsch-Gapp,
• Martin Schäffler,
• Blair D. Johnston,
• Nadine Haberl,
• Christian Pfeiffer,
• Jörg Diendorf,
• Carsten Schleh,
• Stephanie Hirn,
• Manuela Semmler-Behnke,
• Matthias Epple and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1699–1711, doi:10.3762/bjnano.5.180

• sized particles. When calculating the BI relative to the surface areas of the incubated particles then the BIsurf values of all three hydrophobic particles are high but the BIsurf values of the hydrophilic NP remain low. We also estimated the surface coverage of the three proteins on the particle

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• the nanotube surface with proper dispersant molecules. Molecular dynamic simulations allowed us to highlight that the SWCNT surface coverage is systematically ensured by the hydrophobic domain of the amphiphilic dispersant. An increase of hydrophobicity therefore causes weaker inter-tube contacts

Purification of ethanol for highly sensitive self-assembly experiments

• Kathrin Barbe,
• Martin Kind,
• Christian Pfeiffer and
• Andreas Terfort

Beilstein J. Nanotechnol. 2014, 5, 1254–1260, doi:10.3762/bjnano.5.139

• change of thin gold films upon chemisorption of molecular films. For a selected class of compounds, such as alkanethiols, a very good linear correlation between the increase of resistivity and the surface coverage Θ has been established [29][32]. As an initial test, several commercial qualities of

Fringe structures and tunable bandgap width of 2D boron nitride nanosheets

• Peter Feng,
• Muhammad Sajjad,
• Eric Yiming Li,
• Hongxin Zhang,
• Jin Chu,
• Ali Aldalbahi and
• Gerardo Morell

Beilstein J. Nanotechnol. 2014, 5, 1186–1192, doi:10.3762/bjnano.5.130

• presented by Lin [10]. Theoretically, surface treatment can effectively control the band gap of nano BN and plays a crucial role of engineering their electrical and electronic properties. For example for BN nanotubes (BNNT), 50% tube surface coverage with chemisorbed hydrogen atoms would cause the BN band

Adsorption and oxidation of formaldehyde on a polycrystalline Pt film electrode: An in situ IR spectroscopy search for adsorbed reaction intermediates

• Zenonas Jusys and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2014, 5, 747–759, doi:10.3762/bjnano.5.87

• temperatures not only enhance the surface coverage of weakly adsorbed species, but may also increase the time window available for measurements at low COad coverage by slowing down the decomposition or further oxidation of the adsorbed reaction intermediate. For the same reason, we also performed comparable

In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

• Tianxun Gong,
• Douglas Goh,
• Malini Olivo and
• Ken-Tye Yong

Beilstein J. Nanotechnol. 2014, 5, 546–553, doi:10.3762/bjnano.5.64

• -coated AuNRs and thereby producing AuNR formulations with a different surface coverage of PEG-SH and PEO–PPO–PEO molecules. The cytotoxicity between the as-synthesized AuNRs and AuNRs after varying times of washing treatment was also compared. As shown in Figure 3, the as-synthesized AuNR formulation has

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• into a pyrene–methanol solution, followed by the deposition of DNA origami constructs onto the treated substrate. Apparently, the surface coverage of pyrene on the MoS2 was not as smooth as that of 1-pyrenemethylamine (Figure 4a), which might be partially caused by the lower polarity of the pyrene

• structures. Although this might be attributed to the accumulation of H2O molecules on the MoS2 surface caused by the limited surface coverage of pyrene, other mechanisms for disruption of the structure, including the strong van der Waals interactions with pyrene or even pyrene intercalation into the DNA [24

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• of the irradiation doses: (1) the initial formation of nuclei occurs up to a surface coverage of 6–10%; (2) the 1D growth dominates for a coverage up to about 35%; (3) the 2D growth dominates for a coverage above about 35%. We employed Gaussian distributions to describe the probability of surpassing

• of the cross-linked area plotted as a function of the irradiation dose: (1) no CNM forms below the threshold dose of approximately 160 µC/cm2; (2) the formation of nuclei occurs up to a surface coverage of 6–10%; (3) the 1D growth dominates for a coverage of up to about 35% and the required mean dose

Change of the work function of platinum electrodes induced by halide adsorption

• Florian Gossenberger,
• Tanglaw Roman,
• Katrin Forster-Tonigold and
• Axel Groß

Beilstein J. Nanotechnol. 2014, 5, 152–161, doi:10.3762/bjnano.5.15

• is another aspect that needs to be clarified. In a simple model, one may completely neglect the interaction between the adsorbates. In this case, a linear trend would be expected, where θ is the surface coverage and Δμ is the change in the surface dipole moment brought about by the adsorption of a