Effects of gold and PCL- or PLLA-coated silica nanoparticles on brain endothelial cells and the blood–brain barrier

• Aniela Bittner,
• Angélique D. Ducray,
• Hans Rudolf Widmer,
• Michael H. Stoffel and
• Meike Mevissen

Beilstein J. Nanotechnol. 2019, 10, 941–954, doi:10.3762/bjnano.10.95

• co-culture with SH-SY5Y cells were not affected by exposure to PEGylated Au-NPs [24]. Similar results were reported by Trickler et al. using Au-NPs in both a rat and a porcine model of the BBB. Smaller Au-NPs, however, increased the BBB-permeability in the rBMEC monolayer but not the pBMEC monolayer

• -characteristics, namely tight junction (TJ) formation, in rBCEC4 cells. Both, the TJ-associated protein zonula occludens-1 (ZO-1) and the TJ protein occludin, resulted in positive staining (Figure 5A,B). TEM pictures corroborated the formation of TJs between single rBCEC4 cells in a cell monolayer (Figure 5C). A

• possible effect of NP exposure on TJ formation and established TJs was investigated using immunofluorescence staining for ZO-1 (Figure 5D–G). rBCEC4 cells were exposed to PLLA-NPs at a concentration of [24.9 µg/mL] at various time points during and after monolayer and barrier formation. No differences in

Fabrication of silver nanoisland films by pulsed laser deposition for surface-enhanced Raman spectroscopy

• Bogusław Budner,
• Mariusz Kuźma,
• Barbara Nasiłowska,
• Bartosz Bartosewicz,
• Malwina Liszewska and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2019, 10, 882–893, doi:10.3762/bjnano.10.89

• substrates depends on the enhancement factor achieved for the Raman signal. Several ways to calculate the EF have been reported in the literature [23][28][29]. In the simplest case, the EF is determined as the intensity ratio of the selected peak for the tested compound in the form of a monolayer on the SERS

• substrates and in the bulk form [23]. This method, however, is very inaccurate because of the different number of measured molecules of the tested substance contained in a monolayer and in the volume of the material. To obtain better results, the EF was calculated based on the Raman spectrum registered for a

• pMA monolayer adsorbed on the surface of a platinum foil with 99.998% purity. According to literature reports, a pMA monolayer can be made on the surface of platinum, as well as on the surface of silver and gold, a pMA monolayer can be made [30][31]. EF values were calculated according to the

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• of AlOCl and BaFCl (not shown) are similar to the geometry of AcOCl. In Figure 2, we present also the structures of the iodide monolayers YOI and ScOI (the structures of BiOI and LaOI are similar to the one of YOI). It can be noticed that each monolayer has a thickness of five atoms with sublayers

• monolayers CrOF, GaOF, InOF and LaOF are shown in Figure 5. From the DOS, it can be seen that the CrOF monolayer has a finite spin polarisation, and its magnetic moments are ordered ferromagnetically. Also, it is seen that the fluorine atoms contribute to the valence bands for all fluorides monolayers, while

• , and 6.9 eV for CaFBr. In contrast to the other bromides, the BiOBr monolayer exhibits an indirect bandgap with the CBM located at the Γ point and the VBM located along the M–Γ line. Using the GGA, the bandgap of BiOBr is found to be 2.68 eV, which is increased to 4.50 eV when the HSE functional is

Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM

• Loji K. Thomas and
• Michael Reichling

Beilstein J. Nanotechnol. 2019, 10, 804–810, doi:10.3762/bjnano.10.80

• various defects such as cleavage steps, graphite strands, wrinkles/ridges, fiber-like entities, folded-over flakes, broken graphite pieces and other carbon aggregates [5][6][7][8][9][10]. Graphene, a monolayer of graphite, is the thinnest and strongest material ever known [11][12][13] and holds immense

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• energies of Li2Sx absorbed on 1T'-MoS2 monolayer are in the range of 0.31–2.94 eV, which is much higher than on the 2H-phase. The 1T'-MoS2 monolayer shows stronger trapping ability for Li2Sx than the 2H-MoS2 monolayer. The 1T'-MoS2 monolayer can be used as effective anchoring material in cathodes for Li–S

• understood. In this study, we systematically investigated the adsorption of LPSs on 2H-MoS2 and 1T'-MoS2 monolayers with DFT calculation. Our results show that the 1T'-MoS2 monolayer interacts strongly with Li2Sx, which will hinder the shuttle effect. Taking into account the better conductivity, 1T'-MoS2

• '-MoS2 monolayers used in the work are shown in Figure 1a and Figure 1b, respectively. The electronic band structures along high-symmetry points are shown in Figure 1c and Figure 1d, respectively. The 2H-MoS2 monolayer is a semiconductor with a direct bandgap of 1.67 eV, both the conduction band minimum

Towards rare-earth-free white light-emitting diode devices based on the combination of dicyanomethylene and pyranine as organic dyes supported on zinc single-layered hydroxide

• Jeff L. Nyalosaso,
• Rachod Boonsin,
• Pierre Vialat,
• Damien Boyer,
• Geneviève Chadeyron,
• Rachid Mahiou and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 760–770, doi:10.3762/bjnano.10.75

• is to trap the organic molecules by intercalation so as to preserve their optical properties [10][11]. In the solid matrix the molecule dyes are arranged in the interlayer spaces by monolayer particle assembly and a direct anion-exchange procedure in organic media [12]. Depending on the nature of the

Features and advantages of flexible silicon nanowires for SERS applications

• Hrvoje Gebavi,
• Vlatko Gašparić,
• Dubravko Risović,
• Nikola Baran,
• Paweł Henryk Albrycht and
• Mile Ivanda

Beilstein J. Nanotechnol. 2019, 10, 725–734, doi:10.3762/bjnano.10.72

• as much as it did between 10−6 and 10−5 M. It indicates that there is only a certain number of possible active sites on Ag that can host the analyte molecules. The reorientation of 4-MPBA or a shielding of the first analyte monolayer could also contribute to this effect. At a concentration of 10−6 M

The effect of translation on the binding energy for transition-metal porphyrines adsorbed on Ag(111) surface

• Luiza Buimaga-Iarinca and
• Cristian Morari

Beilstein J. Nanotechnol. 2019, 10, 706–717, doi:10.3762/bjnano.10.70

• theoretical [24][25][26] attention. Among the coinage metals typically used for applications, Ag(111) has attracted particular interest [27][28][29]. A complex behavior of the porphyrins on this surface was shown. Parallel orientation with respect to the surface is preferred for sub-monolayer coverage, while

• prefactor in the Boltzmann distribution law, even at a sub-monolayer coverage a large number of molecules are mobile on the surface. Also, following the same argumentation we can say that the direction of migration is not restricted from bridge to hollow positions. While the energy barrier along the bridge

Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

• Imtiaz Ahmad,
• Floor Derkink,
• Tim Boulogne,
• Pantelis Bampoulis,
• Harold J. W. Zandvliet,
• Hidayat Ullah Khan,
• Rahim Jan and
• E. Stefan Kooij

Beilstein J. Nanotechnol. 2019, 10, 696–705, doi:10.3762/bjnano.10.69

• . However, Figure 1A–C displays a montage of SEM images that shows monolayer nanorod deposits on the HOPG terraces, analogous to the results reported previously [51]. Since this work was more focused on the deposition and alignment of the nanorods near the step edges (comparable to the observation

• evaporated leaving behind bright regions of deposits on the surface. SEM images of evaporation-induced deposits at various locations on the HOPG surface: (A) dense deposits of gold nanorods after the first pinning of the contact line; (B) monolayer close-packed arrays on terraces; and (C, D) nanorods

Outstanding chain-extension effect and high UV resistance of polybutylene succinate containing amino-acid-modified layered double hydroxides

• Adam A. Marek,
• Vincent Verney,
• Christine Taviot-Gueho,
• Grazia Totaro,
• Laura Sisti,
• Annamaria Celli and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 684–695, doi:10.3762/bjnano.10.68

• the organic anions (determined using ChemBio 3D ultra 13.0 suite software) leads us to propose a monolayer arrangement for LDH/HIS where the main plane of the molecule is oriented nearly parallel to the hydroxide layer (Figure 2). From the point of charge density, Mg2Al hydroxide layers display an

Commercial polycarbonate track-etched membranes as substrates for low-cost optical sensors

• Paula Martínez-Pérez and
• Jaime García-Rupérez

Beilstein J. Nanotechnol. 2019, 10, 677–683, doi:10.3762/bjnano.10.67

• the development of optical sensors: polycarbonate track-etched (PCTE) membranes. PCTE membranes, which are typically used for size-based filtration [9][10], are reminiscent of the porous structure of a monolayer of porous silicon, a material that has an optical response of a Fabry–Pérot (FP

Ultrathin hydrophobic films based on the metal organic framework UiO-66-COOH(Zr)

• Miguel A. Andrés,
• Clemence Sicard,
• Christian Serre,
• Olivier Roubeau and
• Ignacio Gascón

Beilstein J. Nanotechnol. 2019, 10, 654–665, doi:10.3762/bjnano.10.65

• /surfactant films containing 10 wt % octadecylphoshonic acid (ODP) have been deposited on substrates of different nature by Langmuir–Blodgett (LB) and Langmuir–Schaefer (LS) methods, showing that the presence of even only one MOF/ODP monolayer can increase the water contact angle of highly hydrophilic

• [24] and spray methods [25]. Compared to other methodologies that allow the deposition of MOF thin films, the Langmuir–Blodgett (LB) technique presents some advantages. Previous functionalization of the surface is not necessary and the film obtained can be as thin as one monolayer of MOF particles

• ODP amount contained on the monolayer MOF/ODP film. In addition, a broad feature at 5.7° is present in the MOF/ODP drop-cast sample that corresponds to pure ODP (Supporting Information File 1, Figure S7). Therefore, the crystalline structure of the MOF is preserved upon incorporation of the ODP and

Biomimetic synthesis of Ag-coated glasswing butterfly arrays as ultra-sensitive SERS substrates for efficient trace detection of pesticides

• Guochao Shi,
• Mingli Wang,
• Yanying Zhu,
• Yuhong Wang,
• Xiaoya Yan,
• Xin Sun,
• Haijun Xu and
• Wanli Ma

Beilstein J. Nanotechnol. 2019, 10, 578–588, doi:10.3762/bjnano.10.59

• layer of molecules (submonolayer to monolayer thickness) is adsorbed on the surface of the Ag-G.b.-20 substrate [33]. In the range of relatively low concentration, because all the probe molecules of CV are directly (or closely) adsorbed on the Ag-G.b.-20 substrate surface and SERS exhibits a proximity

• diameter of the illumination spot was ca. 1 µm and the penetration depth was ca. 3 mm. Hence, the value of Nbulk was ca. 1.42 × 1010. According to the above analysis, when the concentration of the CV was 10−6 M, the CV molecules were absorbed as a monolayer on the surface of the Ag-G.b.-20 substrate. The

• points. As plotted in Figure S2b, the RSD values for 915, 1172 and 1532 cm−1 were estimated to be 10.78%, 8.91% and 9.25%. Based on above results, both substrate-by-substrate and point-by-point reproducibility can be achieved with Ag-G.b.-20 substrates, which is likely connected to the monolayer

Hydrophilicity and carbon chain length effects on the gas sensing properties of chemoresistive, self-assembled monolayer carbon nanotube sensors

• Juan Casanova-Cháfer,
• Carla Bittencourt and
• Eduard Llobet

Beilstein J. Nanotechnol. 2019, 10, 565–577, doi:10.3762/bjnano.10.58

• ); self-assembled monolayer (SAM); thiol; Introduction Carbon nanotubes were first observed by Sumio Iijima in 1991 [1] and since then, this nanostructure has been widely used in chemoresistive gas sensors [2][3][4][5] due to the possibility to engineer its sensitivity towards chemicals present in a

Direct observation of the CVD growth of monolayer MoS₂ using in situ optical spectroscopy

• Claudia Beatriz López-Posadas,
• Yaxu Wei,
• Wanfu Shen,
• Daniel Kahr,
• Michael Hohage and
• Lidong Sun

Beilstein J. Nanotechnol. 2019, 10, 557–564, doi:10.3762/bjnano.10.57

• dichalcogenide (2D TMDC) materials. However, it is very challenging to carry out such studies during chemical vapor deposition (CVD). Here, we report the first, real time, in situ study of the CVD growth of 2D TMDCs. More specifically, the CVD growth of a molybdenum disulfide (MoS2) monolayer on sapphire

• substrates has been monitored in situ using differential transmittance spectroscopy (DTS). The growth of the MoS2 monolayer can be precisely followed by observation of the evolution of the characteristic optical features. Consequently, a strong correlation between the growth rate of the MoS2 monolayer and

• spectroscopy; molybdenum disulfide (MoS2) monolayer; two-dimensional transition-metal dichalcogenides (2D TMDC); Introduction Two-dimensional transition metal dichalcogenide (2D TMDC) materials have drawn wide attention because of their fascinating physical and chemical properties [1][2][3][4][5][6]. Given

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO₂ conversion

• Qianyi Cui,
• Gangqiang Qin,
• Weihua Wang,
• Lixiang Sun,
• Aijun Du and
• Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

• ), including Sc to Zn, Mo, Ru, Rh, Pd and Ag, supported on a boron nitride (BN) monolayer with boron vacancies, were investigated as electrocatalysts for the CO2 reduction reaction (CRR) using comprehensive density functional theory (DFT) calculations. The results demonstrate that a single-Mo-atom-doped boron

• nitride (Mo-doped BN) monolayer possesses excellent performance for converting CO2 to CH4 with a relatively low limiting potential of −0.45 V, which is lower than most catalysts for the selective production of CH4 as found in both theoretical and experimental studies. In addition, the formation of OCHO on

• the Mo-doped BN monolayer in the early hydrogenation steps is found to be spontaneous, which is distinct from the conventional catalysts. Mo, as a non-noble element, presents excellent catalytic performance with coordination to the BN monolayer, and is thus a promising transition metal for catalyzing

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• irradiation of 2D materials is usually carried out on substrates [1]. However, the substrate choice is known to play a significant (and sometimes crucial) role in the irradiation process [1][2][3][4][5][6][7]. On one hand, it can increase the stability of a monolayer under irradiation, leading to reduction of

• a resultant defect yield [3]; on the other, it can participate in defect formation in the 2D material through energy transfer from sputtered substrate atoms moving through the monolayer [1][4]. When the energy is suitable, these atoms can become embedded into the 2D material crystal lattice, leading

• to a peculiar doping effect, as it was shown for graphene in [1]. Besides, one cannot exclude participation of displaced recoil atoms [8] that reach the interface but remain within the substrate. Moreover, since there is a charge transfer between the substrate and the monolayer [9][10][11][12], the

Polymorphic self-assembly of pyrazine-based tectons at the solution–solid interface

• Achintya Jana,
• Puneet Mishra and
• Neeladri Das

Beilstein J. Nanotechnol. 2019, 10, 494–499, doi:10.3762/bjnano.10.50

• topographic image of the 2,5-bis(pyridin-4-ylethynyl)pyrazine molecular monolayer at the 1-phenyloctane–HOPG interface. Molecules of 1 self-assemble to form ordered structures on a very large scale up to 500 nm × 500 nm. As clearly discernible in Figure 2a, these molecules undergo polymorphic self-assembly

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• , etc. from group IV–V and X represents the chalcogenides family, X = S, Se, Te, etc. The metal atom M is sandwiched between layers of chalcogenide (X) atoms in the structure X–M–X. The TMDCs show diverse functional properties at the monolayer level in contrast to bulk due to the quantum confinement

• semimetallic nature and single-layer PtSe2 has a semiconducting nature with a bandgap of 1.2 eV. Bilayer PtSe2 is also a semiconducting material but with a slightly smaller band gap than the monolayer material [19]. This layer-dependent conversion of semimetal-to-semiconductor transition has potential for

Removal of toxic heavy metals from river water samples using a porous silica surface modified with a new β-ketoenolic host

• Said Tighadouini,
• Smaail Radi,
• Abderrahman Elidrissi,
• Khadija Haboubi,
• Maryse Bacquet,
• Stéphanie Degoutin,
• Mustapha Zaghrioui and
• Yann Garcia

Beilstein J. Nanotechnol. 2019, 10, 262–273, doi:10.3762/bjnano.10.25

• ). This indicates that the adsorption of metal ions occurs by a monolayer formation in the same limited number of adsorption sites on a homogeneous adsorbent surface. Thermodynamic modeling. The influence of temperature on the adsorption of Zn(II), Pb(II), Cd(II) and Cu(II) ions onto SiNL was evaluated

Scanning probe microscopy for energy-related materials

• Rüdiger Berger,
• Benjamin Grévin,
• Philippe Leclère and
• Yi Zhang

Beilstein J. Nanotechnol. 2019, 10, 132–134, doi:10.3762/bjnano.10.12

• covalently grafted with a monolayer of poly(3-hexylthiophene) functionalized with carboxylic groups [8]. Their study unravels the physical mechanisms taking place locally during the photovoltaic process and its correlation to the nanoscale morphology. Electrochemical energy storage (i.e., in a battery) is a

Pull-off and friction forces of micropatterned elastomers on soft substrates: the effects of pattern length scale and stiffness

• Peter van Assenbergh,
• Marike Fokker,
• Julian Langowski,
• Jan van Esch,
• Marleen Kamperman and
• Dimitra Dodou

Beilstein J. Nanotechnol. 2019, 10, 79–94, doi:10.3762/bjnano.10.8

• this method is that it requires complex instrumentation [28]. Akerboom et al. recently demonstrated a fast and cost-effective alternative method to fabricate micropatterns, in which a colloidal monolayer acts as a three-dimensional template to shape a curable resin [29][30], resulting in arrays of sub

• without a terminal layer on friction. The fabricated sub-microscale dimples had a lower depth than the particle radius. Considering that the time between casting the monolayer with PDMS, degassing and subsequent curing at 68 °C was in the order of 15 min, the uncured PDMS does not fully flow through the

• colloidal monolayer on this timescale, resulting in a limited dimple depth. A strategy to increase the PDMS penetration into the monolayer would be to cure the PDMS at room temperature for 48 h, in which case PDMS remains in a liquid state for much longer. Indeed, we did observe larger dimples and thinner

Apparent tunneling barrier height and local work function of atomic arrays

• Neda Noei,
• Alexander Weismann and
• Richard Berndt

Beilstein J. Nanotechnol. 2018, 9, 3048–3052, doi:10.3762/bjnano.9.283

• ) terrace, a Cu adatom, a monatomic chain, a wide chain, and grooves of monolayer depth with single-atom or wider width. There are systematic differences between the slopes of the terrace data (black line) and the other data sets (colors). On asperities such as adatoms and narrow chains the current varies

• chains and trenches of monolayer height. (a) A Cu chain approximately two atoms wide and a parallel trench. (b) Two wide trenches (approx. 2 and 3 atoms) with deposited single Cu atoms. (c) Monatomic chains and trenches. The images were acquired at (a) V = 20 mV and I = 3 nA and (b, c) V = 100 mV and I

• monolayer depth with single-atom and wider width (approx. 2 atoms) are displayed. The curves are arbitrarily offset along the ordinate for clarity. The terrace data are shown with each curve for comparison. Small undulations of the data are due to low-frequency vibration of the microscope. Apparent barrier

Size limits of magnetic-domain engineering in continuous in-plane exchange-bias prototype films

• Alexander Gaul,
• Daniel Emmrich,
• Timo Ueltzhöffer,
• Henning Huckfeldt,
• Hatice Doğanay,
• Johanna Hackl,
• Muhammad Imtiaz Khan,
• Daniel M. Gottlob,
• Gregor Hartmann,
• André Beyer,
• Dennis Holzinger,
• Slavomír Nemšák,
• Claus M. Schneider,
• Armin Gölzhäuser,
• Günter Reiss and
• Arno Ehresmann

Beilstein J. Nanotechnol. 2018, 9, 2968–2979, doi:10.3762/bjnano.9.276

• were approximated from the density values of pure metals using with x being the mole fraction, x = n/100. The SRIM compound correction was deactivated for all layers except SiO2. Simulations were performed using the monolayer collision mode for 2 × 106 helium ions with a kinetic energy of 15 keV

Ternary nanocomposites of reduced graphene oxide, polyaniline and hexaniobate: hierarchical architecture and high polaron formation

• Claudio H. B. Silva,
• Maria Iliut,
• Christopher Muryn,
• Christian Berger,
• Zachary Coldrick,
• Vera R. L. Constantino,
• Marcia L. A. Temperini and
• Aravind Vijayaraghavan

Beilstein J. Nanotechnol. 2018, 9, 2936–2946, doi:10.3762/bjnano.9.272

• smooth monolayer rGO particles, which are partially restacked when deposited on the Si/SiO2 substrate. The AFM images of the rGO/PANI nanocomposite show similar flake dimensions (ca. 25 μm) as the rGO-25 sample, and no granular particles were observed, as reported for PANI aggregates [36]. On the other