Closed-loop conductance scanning tunneling spectroscopy: demonstrating the equivalence to the open-loop alternative

• Chris Hellenthal,
• Kai Sotthewes,
• Martin H. Siekman,
• E. Stefan Kooij and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2015, 6, 1116–1124, doi:10.3762/bjnano.6.113

• voltage between the tip and sample causes the barrier to lower in an asymmetrical fashion: Any charge travelling between the tip and the sample will induce an image charge of equal magnitude but opposite polarity. In addition to lowering the barrier, the presence of an image charge effect will also narrow

Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

• Kai Braun,
• Xiao Wang,
• Andreas M. Kern,
• Hilmar Adler,
• Heiko Peisert,
• Thomas Chassé,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2015, 6, 1100–1106, doi:10.3762/bjnano.6.111

• 1 nA is kept constant, the negatively charged part of the molecules experiences an increasing attractive force towards the positively charged tip. In the low bias-voltage range, i.e., for |Ub| < 1000 mV, the spectra (Figure 1a and Figure 1b) change only moderately irrespective of the polarity of the

• Figure 2b. If the bias voltage is inverted, (negative tip and positive sample) we observe only a very weak electroluminescence band centered at 725 nm. In contrast, electroluminescence from a pure Au/Au junction induced by inelastic electron tunnelling is independent of the tip polarity [1][2][3][4][5

Fulleropeptide esters as potential self-assembled antioxidants

• Mira S. Bjelaković,
• Tatjana J. Kop,
• Jelena Đorđević and
• Dragana R. Milić

Beilstein J. Nanotechnol. 2015, 6, 1065–1071, doi:10.3762/bjnano.6.107

• concentration. It was shown that the longer peptide chain facilitates the formation of a network structure as a consequence of stronger, arranged interparticle associations. The solid samples of the control compound 1, obtained by precipitation from a CHCl3/CS2 solution with solvents of different polarity (i.e

• morphology were carried out with SEM, using a JEOL JSM-840A instrument, at an acceleration voltage of 30 kV. The solid samples were prepared by precipitation from a CHCl3/CS2 solution with solvents of different polarity (i.e., MeOH, Et2O or hexane), and subsequent drying under vacuum. A small amount of each

Manipulation of magnetic vortex parameters in disk-on-disk nanostructures with various geometry

• Maxim E. Stebliy,
• Alexander G. Kolesnikov,
• Alexey V. Ognev,
• Alexander S. Samardak and
• Ludmila A. Chebotkevich

Beilstein J. Nanotechnol. 2015, 6, 697–703, doi:10.3762/bjnano.6.70

• different combinations of polarity and chirality [2]. Polarity (up or down out-of-plane component of magnetization in the central core of the vortex state) can be controlled by an external magnetic field aligned perpendicular to a disk plane. This method is complicated to be used for microelectronic

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

• shown. The sample was transferred from the UHV chamber to the STM cell and then immersed in high purity water (see Experimental section for details). STM images of the surface shown in Figure 2 were recorded in water after approximately two hours of immersion. In the chosen tip polarity (the sample is

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• alignment layers. To avoid this issue, DC bias has been substituted by a low frequency (0.5 Hz) AC square wave to which the low amplitude AC probe voltage signal is added up (Figure 7). Being a square signal, reorientation of the LC is minimally affected by polarity changes. However, sampling is performed

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• fluorochrome can be monitored independently of the fluorochrome concentration [102]. FLIM gains its information from the fluorescence decay curves and applications of this technique include environmental sensing of, amongst others, polarity, local pH, and calcium concentrations, as well as the study of protein

Oxygen-plasma-modified biomimetic nanofibrous scaffolds for enhanced compatibility of cardiovascular implants

• Anna Maria Pappa,
• Varvara Karagkiozaki,
• Silke Krol,
• Spyros Kassavetis,
• Dimitris Konstantinou,
• Charalampos Pitsalidis,
• Lazaros Tzounis,
• Nikos Pliatsikas and
• Stergios Logothetidis

Beilstein J. Nanotechnol. 2015, 6, 254–262, doi:10.3762/bjnano.6.24

• functional groups are created. This leads to an increase in the polarity and the surface energy, resulting in a roughened topography. Higher plasma power (P = 40 W) significantly decreased Ra resulting into smoother nanofibrous surfaces compared to the untreated samples, due to the partial polymer melting

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

• Johannes Ostermann,
• Christian Schmidtke,
• Christopher Wolter,
• Jan-Philip Merkl,
• Hauke Kloust and
• Horst Weller

Beilstein J. Nanotechnol. 2015, 6, 232–242, doi:10.3762/bjnano.6.22

• the polymers were determined based on the varying fluorescence properties of pyrene, depending on the polarity of the surrounding medium [21]. The values correlate well with the polymer size and lie between 6.0 × 10−7 M for the smallest and 1.5 × 10−7 M for the biggest polymer. Encapsulation methods

Kelvin probe force microscopy in liquid using electrochemical force microscopy

• Liam Collins,
• Stephen Jesse,
• Jason I. Kilpatrick,
• Alexander Tselev,
• M. Baris Okatan,
• Sergei V. Kalinin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2015, 6, 201–214, doi:10.3762/bjnano.6.19

• () which contains information on the polarity and magnitude of the signal. Little to no relaxation of the electrostatic force is observed, with following the applied bias, and therefore satisfying the second principle of KPFM, a time-invariant electrostatic response. This is expected for a purely

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• formation of Cu@Fe3O4 heterodimers with different morphologies based on the use of solvents of various polarity (top) and corresponding (HR-)TEM images of (a, b) cube-shape, (c, d) cloverleaf-shape Cu@Fe3O4 heterodimerparticles (bottom). Reproduced with permission from [57]. Copyright 2011 The Royal Society

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

• particle compartment, POS particles show higher versatility with respect to the variety of possible functionalizations. This makes it possible to change the polarity of the particles. Due to that, the poly(organosiloxane) NPs are a suitable system for a very interesting application in the field of

• particle characteristics to the biological responses that these particles induce. With the work presented here, a well-characterized system of SiO2-based nanomaterials is exhibited which allows for variations in surface properties (surface charge and polarity) as well as in the mechanism of colloidal

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

• this case, CH3CN did not act as a simple “washing” solvent but rather induced a variation of the conformation of the foldamers due to the solvophobic effect associated to the increase of solvent polarity on passing from chlorinated solvents to CH3CN. A recent and interesting way to get a reversible

Synthesis of hydrophobic photoluminescent carbon nanodots by using L-tyrosine and citric acid through a thermal oxidation route

• Venkatesh Gude

Beilstein J. Nanotechnol. 2014, 5, 1513–1522, doi:10.3762/bjnano.5.164

• relaxation time of the solvent is lower or comparable to the fluorescence life time, which depends on the polarity of the chosen solvent [36]. This explanation contradicts the expected electron–hole pair mechanism of CNDs from earlier reports [2][5]. Therefore, further spectroscopic investigations are

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• would result in a temperature difference between the tunnelling tip and the sample, a thermovoltage in the tunnelling gap would occur. This voltage would also be measured by our STP setup and would be independent of the polarity of the transverse current. Since we do not observe this effect, heating of

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• coating and DI water. The interface of the layers will have a tendency to be electrostatically charged. When the applied voltage has an opposite polarity, the charging is additive. As a result, there will be a discharge current [77] which may lead to a damage of the brittle PS coating. To avoid the damage

Designing magnetic superlattices that are composed of single domain nanomagnets

• Derek M. Forrester,
• Feodor V. Kusmartsev and
• Endre Kovács

Beilstein J. Nanotechnol. 2014, 5, 956–963, doi:10.3762/bjnano.5.109

• nanomagnet in a superlattice. Anti-parallel states occur when the magnetic moments point with opposite polarity along the easy-axes and are shown by a series of plateaus, in between saturation states (a parallel phase P occurs when there are no AP or AF states and is usually typical of ferromagnetically

Shape-selected nanocrystals for in situ spectro-electrochemistry studies on structurally well defined surfaces under controlled electrolyte transport: A combined in situ ATR-FTIR/online DEMS investigation of CO electrooxidation on Pt

• Sylvain Brimaud,
• Zenonas Jusys and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2014, 5, 735–746, doi:10.3762/bjnano.5.86

• (bi)sulfate anions recorded on the (111)-NC and (100)-NC samples. The inversion of the band polarity (abnormal IR effect) apparent from these spectra is well known for nanoparticle samples and has already been discussed elsewhere [21][33]. This does not, however, limit the interpretation of these

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

• MoS2 surface adopt many different structures, most likely originating partially from intra-strand base pairing and partially from the strong interaction between DNA bases and the MoS2 surface [11]. Recent studies indicate that the MoS2 surfaces have high polarity and hydrophilicity [20], which lead DNA

• 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

Charge and spin transport in mesoscopic superconductors

• M. J. Wolf,
• F. Hübler,
• S. Kolenda and
• D. Beckmann

Beilstein J. Nanotechnol. 2014, 5, 180–185, doi:10.3762/bjnano.5.18

• polarity. These features can be attributed to spin injection into the Zeeman-split density of states of the superconductor [17][18][22][26], which is probed by the ferromagnetic detector in this configuration. Spin-polarized tunneling can be described by two independent conductances g↓ and g↑ for the two

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

• halogen atom. Obviously, this model is applicable only at low coverages in Figure 2. In a more advanced model, the electrostatic interaction between adjacent dipoles is taken into account by assuming that the mutual repulsion of the dipoles leads to a decrease in the polarity of the halogen–metal bond

Exploring the retention properties of CaF₂ nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

• Matthias Wasem,
• Joachim Köser,
• Sylvia Hess,
• Enrico Gnecco and
• Ernst Meyer

Beilstein J. Nanotechnol. 2014, 5, 36–43, doi:10.3762/bjnano.5.4

• value, which come from the enamel and the ionic species present in the liquid [36][37][38]. In our case, we speculate that the surface polarity of the enamel strongly influenced the retention of the adsorbed CaF2 nanoparticles. The matching of the polarity of the substrate and the nanoparticle resulted

Noise performance of frequency modulation Kelvin force microscopy

• Heinrich Diesinger,
• Dominique Deresmes and
• Thierry Mélin

Beilstein J. Nanotechnol. 2014, 5, 1–18, doi:10.3762/bjnano.5.1

• the input is the VK component of the tip bias. The tip voltage superposition has two purposes: first to extract the polarity information of the gap voltage mismatch, and second to share the PLL bandwidth between Kelvin and distance controller: van-der-Waals and electrostatic interaction both shift the

Adsorption of the ionic liquid [BMP][TFSA] on Au(111) and Ag(111): substrate effects on the structure formation investigated by STM

• Benedikt Uhl,
• Florian Buchner,
• Dorothea Alwast,
• Nadja Wagner and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2013, 4, 903–918, doi:10.3762/bjnano.4.102

• , high polarity, nearly vanishing vapour pressure and their wide electrochemical window [1][2][3]. Because of the enormous flexibility in varying the combination and nature of cations and anions [4], e.g., by using different alkyl chain lengths at the cations [2][5][6][7] it is possible to systematically

Site-selective growth of surface-anchored metal-organic frameworks on self-assembled monolayer patterns prepared by AFM nanografting

• Tatjana Ladnorg,
• Alexander Welle,
• Stefan Heißler,
• Christof Wöll and
• Hartmut Gliemann

Beilstein J. Nanotechnol. 2013, 4, 638–648, doi:10.3762/bjnano.4.71

• µm × 12 µm was prepared. The corresponding AFM-phase image is shown in Figure 4a. According to the results in Figure 3c, the grafted rectangular MPA coated structures show a significantly different phase shift compared to the 1-decanethiolate matrix SAM. The result of the negative polarity total

• polarity total secondary ion mapping. (c) High mass resolution SIMS data for DT (black line) and MPA (red line), the peak at m/z 371 in (c) is attributed to [AuSC10H22]−, the Au cluster ion of DT, (d) as (c) the peak at m/z 499 is assigned to [Au2SC3H5O2]−, the Au cluster ion of MPA. Other characteristic