Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• , this stability decreases proportionally. Hence, to increase the stability of the concentrated collidal solution, the originally citrate-capped AuNPs were functionalized with folic acid molecules by electrostatic interaction between the negative surface of the particles and the positive amino groups of

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• are fundamentally important and also can be applied for designing and modelling of surface plasmon resonance based sensor applications. Keywords: 3-aminopropyletriethoxysilane; electrostatic interaction; functionalization; gold nanoparticles; self-assembled monolayer; self-organization; Introduction

• the orientation of APTES molecules favoring the attachment of metal nanoparticles as described in Figure 2 (type I, II). However, NH2-terminated silanized glass (Figure 2, type IV) surfaces could lead to large amount of AuNPs attached to the amine groups through electrostatic interaction as shown in

• ]. Upon the deposition of AuNPs on APTES-functionalized glass substrate, the λmax intensity shifted back to its original binding energy of pure glass surface, 7.4 eV. This suggests that electrons are donated from AuNPs to APTES molecules through an electrostatic interaction during the attachment to the

Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

• Joseba Irigoyen,
• Nikolaos Politakos,
• Eleftheria Diamanti,
• Elena Rojas,
• Marco Marradi,
• Raquel Ledezma,
• Layza Arizmendi,
• J. Alberto Rodríguez,
• Ronald F. Ziolo and
• Sergio E. Moya

Beilstein J. Nanotechnol. 2015, 6, 2310–2318, doi:10.3762/bjnano.6.237

• strength. The assembly of exfoliated GO was done in water at pH 10 to avoid the screening of the charges on the GO. If present, screening the GO charges could lead to a stronger interaction between GO sheets in solution leading to aggregation. Charge screening would also eventually reduce the electrostatic

• interaction between the GO and the polyelectrolyte on the cell, which would be unfavourable for assembly. Between each GO deposition, we deposited either one layer of PAH or three layers of PAH/PSS/PAH. Since the assembly of one layer of PAH between the GO layers may not be sufficient to lead to a complete

Electroviscous effect on fluid drag in a microchannel with large zeta potential

• Dalei Jing and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2015, 6, 2207–2216, doi:10.3762/bjnano.6.226

• can become spontaneously charged based on different mechanisms, such as adsorption of ions or deionization [5][14][15][16]. The charged solid–liquid interface affects the ion distribution and causes local net charge in the liquid. Because of the electrostatic interaction, the counter-ions (ions having

• of electrostatic interaction, is formed next to the solid surface. Above that, the diffuse layer, a thin layer consisting of mobile ions, is formed because of loose electrostatic force and thermal diffusion. Both the adsorbed layer and the diffuse layer constitute an electric double layer (EDL) [5

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• lateral resolution and pronounced capacitive averaging of the locally measured contact potential difference. Furthermore, local changes in the strength of the electrostatic interaction between tip and surface easily lead to topography crosstalk seen in the surface potential. To take full advantage of the

Electrospray deposition of organic molecules on bulk insulator surfaces

• Antoine Hinaut,
• Rémy Pawlak,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2015, 6, 1927–1934, doi:10.3762/bjnano.6.195

• -cyanophenyl groups are known to enhance the binding to ionic substrates by electrostatic interaction [37][38]. For the UHV-ESI deposition, molecules were diluted at 1 μL/mL in a mixture of toluene and isopropanol with a 2:1 ratio. Deposition was performed for 5 min at a constant rate of injected solution of 5

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

• synthesized, Au nanoparticle, colloid solution for about 2 h under continuous stirring conditions. The Au nanoparticles were assumed to attach to the polymer/Fe3O4 complex via electrostatic interaction, which was confirmed by the discoloration of the mixture. After washing with deionized water and adding

Probing fibronectin–antibody interactions using AFM force spectroscopy and lateral force microscopy

• Andrzej J. Kulik,
• Małgorzata Lekka,
• Kyumin Lee,
• Grazyna Pyka-Fościak and
• Wieslaw Nowak

Beilstein J. Nanotechnol. 2015, 6, 1164–1175, doi:10.3762/bjnano.6.118

• that after deposition on a mica surface, a layer composed of single molecules was formed. The compact form of FN may be rationalized by considering the electrostatic interaction occurring between different parts of the molecule. Also, the alteration of a protein conformation can be induced by a

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• . The electrostatic interaction with the environment leads to the localization of the frontier orbitals. Energy levels of Al(Op)3 calculated with different conditions, namely, HOMO and LUMO in vacuum (vac.) and in a self-consistent electrostatic environment (env.), with electron affinity (EA) and

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

• pzc is also the electrostatic interaction between the positively (protonated) charged tip and the negatively charged surface (caused by the specific adsorption of sulfate). The irreversibility may also be caused by a mutual penetration of the two double layers (that of the surface and that of the tip

Influence of spurious resonances on the interaction force in dynamic AFM

• Luca Costa and
• Mario S. Rodrigues

Beilstein J. Nanotechnol. 2015, 6, 420–427, doi:10.3762/bjnano.6.42

• sample which results in an electrostatic interaction. Three approach curves were taken at selected arbitrary frequencies (Figure 4b) and Equation 17 was used to account for the interaction. All the measurements provide the same force gradient (Figure 4e) regardless of the presence of spurious resonances

• by Equation 15. For 0 < α < 1, the solution lies somewhere between that given by Equation 6 and Equation 15. The red curve shows the solution for α = 2. Characterization of a tip–sample electrostatic interaction at resonance (gray) and off resonance (red and brown). a) Cantilever Brownian motion; b

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

• two major paths for noncovalent π-stacking interactions involving aromatic rings to occur: sandwich and parallel-displaced. Sandwich is a π-stacking geometry that occurs between the benzene groups through electrostatic repulsion, whereas the electrostatic interaction between the benzenes will result

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

• average, negatively charged. Electrostatic interaction with negatively charged COOH–PEG nanorods should therefore be repulsive, comparable to the bare glass substrates. In contrast, amines are known to interact with the negatively charged cell membrane. It is therefore likely that an anchoring of the

• was found that about 20% of apical applied CTAB nanorods enter the cell, whereas only a fraction of a percent of PEG nanorods (regardless of end group) were internalized. We attributed the differences in uptake to the surface charge of the particles favoring or disfavoring electrostatic interaction

Two-dimensional and tubular structures of misfit compounds: Structural and electronic properties

• Tommy Lorenz,
• Jan-Ole Joswig and
• Gotthard Seifert

Beilstein J. Nanotechnol. 2014, 5, 2171–2178, doi:10.3762/bjnano.5.226

• strong, attractive, electrostatic interaction between the two sublayers is the origin of the stability of the misfit compounds within the concept of cationic coupling. To conclude this section, we will briefly mention the so-called graphite intercalation compounds (GICs) [43] that consist of several

Controlling the dispersion of supported polyoxometalate heterogeneous catalysts: impact of hybridization and the role of hydrophilicity–hydrophobicity balance and supramolecularity

• Gijo Raj,
• Colas Swalus,
• Eglantine Arendt,
• Pierre Eloy,
• Michel Devillers and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 1749–1759, doi:10.3762/bjnano.5.185

• dependent on the interaction between various factors such as the type of hybridization (i.e., through electrostatic interaction or covalent bonding), the nature of the POM building block (formula, charge density), and the chemical nature and hydrophilic or hydrophobic character of the surface on which the

• driven through the electrostatic interaction of POM anions with the positively charged DODA surfactant. Firstly, we study the DODA–POM hybrids deposited on HOPG. Drop-casting of a small amount (about 9.5 µL) of a very dilute solution (0.025 g·L−1) allows for the formation of molecular layers that are of

Model systems for studying cell adhesion and biomimetic actin networks

• Dorothea Brüggemann,
• Johannes P. Frohnmayer and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

• reconstitution procedure did not change the lipid composition of the vesicles. Charged lipids were found to increase the solubility of talin in the membrane drastically, thus indicating an electrostatic interaction of talin with lipid bilayers. Based on these findings, reconstituted talin in lipid vesicles was

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag₂CrO₄

• Difa Xu,
• Shaowen Cao,
• Jinfeng Zhang,
• Bei Cheng and
• Jiaguo Yu

Beilstein J. Nanotechnol. 2014, 5, 658–666, doi:10.3762/bjnano.5.77

• electrostatic interaction. Therefore, the photocatalytic activity of the as-prepared Ag2CrO4 samples is evaluated through MB degradation under visible-light irradiation. Without any photocatalyst, no obvious MB degradation is observed under visible-light irradiation. For comparison, P25 (commercial TiO2

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

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

• electrostatic interaction between the ion pairs with increasing coverage, leaving the former configuration energetically less favourable at coverages above 0.8 ML compared to a structure with both species in direct contact with the surface. Overall, though structural resolution of the IL adlayer was not

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

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

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

• University, Minsk, Belarus 10.3762/bjnano.4.101 Abstract The photoexcitation energy transfer is found and investigated in complexes of CdSe/ZnS cationic quantum dots and chlorin e6 molecules formed by covalent bonding and electrostatic interaction in aqueous solution and in porous track membranes. The

• cross-linking reagent was performed. Using PEG as an additional QD shell resulted in an increase of the average distance between the QD and Ce6 molecules in the complexes to ≈5.5 nm. For the complexes, formed via electrostatic interaction, the hydrophobic CdSe/ZnS/TOPO QDs with a core diameter of 5.0 nm

• into the membranes due to electrostatic interaction with the carboxyl groups on the inner surface and in the loosened layer on the track pore wall. Membranes with embedded QDs were impregnated by aqueous solutions of Ce6 for formation of the QDs/Ce6 complexes. In order to study the dependence of the

Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

• Hlengisizwe Ndlovu,
• Alison E. Ashcroft,
• Sheena E. Radford and
• Sarah A. Harris

Beilstein J. Nanotechnol. 2013, 4, 429–440, doi:10.3762/bjnano.4.50

• in each of the two stacked β-sheets, we observe a correlation between the mean peak force and the intersheet electrostatic interaction energies (Table 1) that arise due to the unique packing arrangements of the monomer β-strands. The Class1-P polymorph has the most favourable electrostatic energy

• favourable electrostatic interaction between the sheets of the three. The fact that the Class 6 polymorph is comprised of antiparallel β-sheets stacked in a parallel configuration places it intermediate between the other two. The correlation between the peak force and the electrostatic interfacial energy

Dipole-driven self-organization of zwitterionic molecules on alkali halide surfaces

• Laurent Nony,
• Franck Bocquet,
• Franck Para,
• Frédéric Chérioux,
• Eric Duverger,
• Frank Palmino,
• Vincent Luzet and
• Christian Loppacher

Beilstein J. Nanotechnol. 2012, 3, 285–293, doi:10.3762/bjnano.3.32

• described in [9][19]), or is it due to the electrostatic interaction between the molecular dipole and the rows of charges present along the direction? The first question of whether the Moiré pattern is formed due to coincidences between the two quadratic lattices of the substrate cKCl and the molecules

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• surface dipoles with a component pointing along the normal to the surface. These findings are interpreted with the help of numerical simulations. It is shown that the surface–molecule interaction is dominated by the electrostatic interaction of the cyano groups with the K+ ions of the substrate. The

• equipped with six flexible propyl chains ending with dipolar CN groups. These groups were proven recently to behave as strong anchoring entities for a truxene derivative adsorbed on KBr(001) [10][11] due to their efficient electrostatic interaction with the K+ ions of the surface. Results Low coverage

• bound to the surface by the electrostatic interaction between its CN groups and K+ ions. The flexibility of the propyl chains allows the molecule to reach five K+ ions. One of the chains cannot bind and its CN group stays at a larger distance from the surface (Figure 9b). The N atoms of the CN groups

A measurement of the hysteresis loop in force-spectroscopy curves using a tuning-fork atomic force microscope

• Manfred Lange,
• Dennis van Vörden and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 207–212, doi:10.3762/bjnano.3.23

• ; tunneling current I = 60 pA. (a) Frequency-shift versus distance curve. The contribution from the long-range forces has been subtracted. The spectroscopy measurement was recorded with an oscillation amplitude of 2.8 Å and a bias voltage of 0.1 V to eliminate the electrostatic interaction. The black curves