Mobility of charge carriers in self-assembled monolayers

• Zhihua Fu,
• Tatjana Ladnorg,
• Hartmut Gliemann,
• Alexander Welle,
• Asif Bashir,
• Michael Rohwerder,
• Qiang Zhang,
• Björn Schüpbach,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2019, 10, 2449–2458, doi:10.3762/bjnano.10.235

• study charge transport within 2D layers of organic semi-conductors (OSCs) using atomic force microscopy (AFM)-based lithography applied to self-assembled monolayers (SAMs), fabricated from appropriate organothiols. The extent of lateral charge transport was investigated by insulating pre-defined patches

• , using an approach where measurements are carried out for structurally well-defined self-assembled monolayers (SAMs) [9], fabricated from appropriate organothiols. A very large number of organothiolates have been found to form monolayers of high structural quality on Au substrates [10], with a pronounced

• before the SAM preparation. The formation of the PAT monolayers was carried out by immersing the substrates into 0.1 mM absolute ethanolic solution (≥99.8%, AnalaR NORMAPUR® ACS, Reag. Ph. Eur. zur Analyse) of PAT for 24 h at RT and, optionally, at an elevated temperature (70 °C). The samples were

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• sensitivity (up to 17 times), selectivity and improves the response dynamics of the sensors. Keywords: gold-decorated MWCNTs; multiwall carbon nanotubes (MWCNTs); self-assembled monolayers (SAMs); sensitivity; selectivity; vapour sensor; Introduction Aromatic volatile organic compounds (VOCs) such as

• effect of nucleation. The power and time required for the plasma beam aperture within the cell were optimized and fixed to 30 W and 10 seconds, respectively. Functionalisation with self-assembled monolayers (SAMs) The Au-decorated MWCNT substrate was further functionalized with an alkanethiol self

• performance [25][26]. FTIR characterisation In order to ensure that the HDT monolayers are formed and well immobilized on the Au-MWCNT layers, we used FTIR spectroscopy. Figure 3 shows the infrared spectra, in absorbance mode, of both Au-MWCNT and HDT/Au-MWCNT layers. When analysing and comparing the infrared

Adsorption and desorption of self-assembled L-cysteine monolayers on nanoporous gold monitored by in situ resistometry

• Elisabeth Hengge,
• Eva-Maria Steyskal,
• Rupert Bachler,
• Alexander Dennig,
• Bernd Nidetzky and
• Roland Würschum

Beilstein J. Nanotechnol. 2019, 10, 2275–2279, doi:10.3762/bjnano.10.219

• 12, A-8010 Graz, Austria 10.3762/bjnano.10.219 Abstract Surface modifications of nanoporous metals have become a highly attractive research field as they exhibit great potential for various applications, especially in biotechnology. Using self-assembled monolayers is one of the most promising

• approaches to modify a gold surface. However, only few techniques are capable of characterizing the formation of these monolayers on porous substrates. Here, we present a method to in situ monitor the adsorption and desorption of self-assembled monolayers on nanoporous gold by resistometry, using cysteine as

• resistometry. From the desorption peak related to the (111) surface of the structure, which is associated with a resistance change of 4.8%, an initial surface coverage of 0.48 monolayers of cysteine could be estimated. Keywords: L-cysteine; in situ resistometry; nanoporous gold; self-assembled monolayer (SAM

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• this case, the domains formed by DPPC bilayers of ≈5 nm in height are omnipresent, while only a few domains of monolayers are observed (Figure 11Ba). It is seen that IONP@C2H5OEG8Den are preferentially located in the regions of the wafer that are devoid of phospholipid domains. The height profile

Ion mobility and material transport on KBr in air as a function of the relative humidity

• Dominik J. Kirpal,
• Korbinian Pürckhauer,
• Alfred J. Weymouth and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2019, 10, 2084–2093, doi:10.3762/bjnano.10.203

• to be taken into account that measurements at such low pressure rather relate to the outer atmosphere than to ambient conditions. However similar observations have been made by Asay et al. under ambient conditions, who showed on silicon oxide the growth of three monolayers up to RH = 30%, an

• additional layer forming by increasing RH to 60% and further growth of the water film up to 2.7 nm (ca. 10 monolayers) thickness at higher humidities [1]. On the atomic level, water and adsorbed molecules can arrange according to the surface structure and form ordered hydration layers that are also referred

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• cm2·V−1·s−1 [17]. Therefore, it is of profound significance to explore the thermoelectric properties of MoO3 monolayers and discuss the effect of O vacancies on it. Computational methods In this work, we evaluate the thermoelectric properties of a MoO3 monolayer by Boltzmann transport theory and first

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• monolayers [133][134], Langmuir–Blodgett films [135][136][137], and layer-by-layer assembly [138][139][140][141] on sensors and related devices is a key nanoarchitectonics step for sensor fabrication. For example, Furusawa et al. immobilized nickel-nitrilotriacetic acid within a self-assembled monolayer on

• efforts. Guo and co-workers fabricated a field-effect transistor with monolayers and multilayers of pentathiophene-type organic semiconductor for melamine detection [144] (Figure 7). The used dialkoxyphenyl pentathiophene derivative has a semiconductive pentathiophene core sandwiched by two insulating C12

• semiconductive monolayers was also demonstrated by Chan and co-workers who successfully prepared semiconductor monolayer crystals of 2,9-didecyldinaphtho[2,3-b:2’,3’-f]thieno[3,2-b]thiophene on the millimeter scale [145]. The semiconductor crystals encapsulated within poly(methyl methacrylate) exhibited a

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• receptors in monolayers at the air–water interface can be controlled by macroscopic lateral motion such as mechanical compression and expansion of the monolayers. Macroscopic mechanical deformation of the interfacial media at the scale of centimetres or metres can regulate nanometre-scale conformational

• mechanisms of formation and transformation of zero-dimensional structures within two-dimensional media (dot-dispersed monolayers of block copolymers) [200]. Self-assembled monolayers of polystyrene-b-poly(4-vinylpyridine) and its supramolecular complex with 3-n-pentadecylphenol at the air–water interface

• mechanism might be generalized for zero-dimensional dot-dispersed monolayers of block-copolymers. Wen and co-workers reported the drastic modification of two-dimensionally patterned Langmuir–Blodgett (LB) films of polystyrene-b-poly(2-vinylpyridine) transferred from the air–water interface through acetone

Pure and mixed ordered monolayers of tetracyano-2,6-naphthoquinodimethane and hexathiapentacene on the Ag(100) surface

• Robert Harbers,
• Timo Heepenstrick,
• Dmitrii F. Perepichka and
• Moritz Sokolowski

Beilstein J. Nanotechnol. 2019, 10, 1188–1199, doi:10.3762/bjnano.10.118

• /bjnano.10.118 Abstract We report on mixed ordered monolayers of the electron acceptor-type molecule tetracyano-2,6-naphthoquinodimethane (TNAP) and the electron donor-type molecule hexathiapentacene (HTPEN). This investigation was motivated by the general question which type of mixed stoichiometric

• formation of the mixed structure occurs spontaneously. An important motif for the structure formation is given by hydrogen bonds between the TNAP molecules. Both molecules, TNAP and HTPEN also form well-ordered monolayers on the Ag(100) surface on their own. In all structures, the molecules are adsorbed in

• Ordered monolayers on surfaces that are stoichiometrically composed of two different organic molecules have attracted strong interest in recent years [1][2][3]. One general motivation is to find out which ordered structures are formed in relation to the compositions of the layers and the different types

Revisiting semicontinuous silver films as surface-enhanced Raman spectroscopy substrates

• Malwina Liszewska,
• Bogusław Budner,
• Małgorzata Norek,
• Bartłomiej J. Jankiewicz and
• Piotr Nyga

Beilstein J. Nanotechnol. 2019, 10, 1048–1055, doi:10.3762/bjnano.10.105

• few examples. Gold and silver nanostructured surfaces on substrates can be fabricated by self-assembly of colloidal particles into monolayers [16], in the form of island films by seeding with nanoparticles followed by a reduction of metal salt [17][18], or in the form of other high surface area

Enhanced inhibition of influenza virus infection by peptide–noble-metal nanoparticle conjugates

• Zaid K. Alghrair,
• David G. Fernig and
• Bahram Ebrahimi

Beilstein J. Nanotechnol. 2019, 10, 1038–1047, doi:10.3762/bjnano.10.104

• in 6-well plates (STARLAB international, Hamburg, Germany), 106 cells/well) for two days. At confluence, monolayers of MDCK cells were then infected with a serial dilution of influenza virus inoculum (sufficient to obtain approximately 100 plaques per well) for 1 h at 37 °C on a rocking platform. An

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• size and the ratio of Au atoms to ligands of AuNCs. X-ray photoelectron spectroscopy (XPS) has also been applied to observe the molecular dependence on the gold and sulfur chemical state of organosulfur monolayers of the fractions. The photoluminescence spectra of these AuNCs in the range of 900–790 nm

• protective layer of organic molecules [2]. These clusters are considered to be a hybrid system of small molecules and macroscopic materials, and are of great interest to the properties of gold core and organic monolayers [3]. The stable monolayer-protected NCs have enabled experiments to be carried out that

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

• statistically significant increase over time (Figure 7A). After NP exposure ([24.9 µg/mL] PCL-NPs or [160.3 µg/mL] Au-NPs for 24 h) and DMSO stimulation on DIV2, no changes were observed in PCL-NP-treated cell monolayers. However, as expected, DMSO stimulation resulted in a strong decrease of TEER on DIV3 as

• Figure 7B and Figure 7C. Furthermore, no difference between PCL- and Au-NP-exposed cell monolayers was detected. Overall, cell monolayers are less permeable to 70 kDa FITC dextran (Figure 7C) than to 4.4 kDa TRITC dextran (Figure 7B). Discussion A concentration- and time-dependent effect of exposure to

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

• 1007 cm−1 is 9.66, 9.79 and 7.17 for 532, 633 and 785 nm excitation respectively. The spread of the intensity ratio of the peak at 1086 cm−1 relative to the other peaks is also very similar for all excitation wavelengths. In the case of monolayers of pMA in sample C, large changes in the shape of the

• , respectively. The acquisition time and the number of acquisitions for all excitation wavelengths were set to 10 s and 5 s, respectively. For SERS measurements, the pMA monolayers were deposited on the fabricated silver nanoislands. For this purpose, samples with deposited SNIFs were placed in Petri dishes and

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

• Technology (KAIST), Yuseong-gu, Daejeon 305-701, Korea Physics/Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3, 20500 Turku, Finland 10.3762/bjnano.10.82 Abstract Using density functional theory, we study the electronic properties of several halide monolayers. We show that their

• theory; electronic properties; halide monolayers; Introduction The discovery of graphene [1] by exfoliation [2] opened a new era in several domains of science. Graphene has attracted great attention due to its unique properties [3] and because it offers many advantages in comparison with more common

• ] was used. Similar parameters were employed for hybrid Heyd–Scuseria–Ernzerhof (HSE) calculations [38], that were performed to obtain accurate values for the bandgap. Sufficient spacing (more than 17 Å) was put between the monolayers to avoid significant interactions between the periodically repeated

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

• batteries has been demonstrated as an effective way to overcome the shuttle effect and enhance the cycling stability. In this work, the anchoring effects of 2H-MoS2 and 1T'-MoS2 monolayers for Li–S batteries were investigated by using density functional theory calculations. It was found that the binding

• 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

• monolayers can be used as a conductive anchoring material to design advanced Li–S batteries. Results and Discussion Both 2H-MoS2 and 1T'-MoS2 monolayers exhibit a structure with three atomic layers, in which the Mo atomic layer is sandwiched by two S atomic layers. The 6 × 6 supercells for 2H-MoS2 and 1T

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

• temperature and thickness were reported in [26]. 4-MPBA was chosen as a SERS test molecule because of the strong affinity between the thiol group and metal surfaces (Ag or Au) as well as because of the easy formation of self-assembled monolayers (SAMs) [27]. Furthermore, the benzene ring is orientation

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

• , which is especially interesting for the development of MOF-based devices that require the use of very small MOF quantities. In some recent studies, we have reported the fabrication at the air–water interface of dense monolayers of nanoparticles of MIL-101(Cr) and MIL-96(Al) MOFs that can be transferred

• investigate the structure of the hydrophobic films obtained, pure ODP LB films and mixed MOF/ODP LB films transferred onto mica were analyzed by AFM (Figure 5). The study of pure ODP monolayers showed that the films present some defects and pinholes, which allow a monolayer thickness between 2 and 3 nm to be

• determined. This value is in good agreement with the thickness previously reported for ODP monolayers deposited onto silver or gold substrates [33] and reveals that molecules in the film adopt an almost vertical position. Moreover, some domains of different sizes and heights up to 25 nm can be observed

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

• , Belgium 10.3762/bjnano.10.58 Abstract Here we describe the development of chemoresistive sensors employing oxygen-plasma-treated, Au-decorated multiwall carbon nanotubes (MWCNTs) functionalized with self-assembled monolayers (SAMs) of thiols. For the first time, the effects of the length of the carbon

• approach, carbon nanotubes act as support and charge transport transducing elements while the recognition function is performed by grafted molecules. Two examples of this have consisted of obtaining thiol-functionalized carbon nanotube buckypapers [27] or self-assembled monolayers (SAMs) of thiol molecules

• monolayers: 3-mercaptopropanoic acid (C3H6O2S) and 16-mercaptohexadecanoic acid (C16H32O2S) as hydrophilic molecules, and 1-propanethiol (C3H8S) and 1-hexadecanethiol (C16H34S) as more hydrophobic molecules. Additionally, control sensors were produced, which integrated bare Au-decorated MWCNTs, in order to

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

• temperature continues to increase even at the beginning of section III (see Figure 2e). Conclusion In conclusion, we have successfully grown MoS2 monolayers on both sides of the c-plane of double polished sapphire substrates using CVD. The monolayers on both sides of the substrate were homogeneously

• distributed over the 10 × 10 mm substrate surfaces. Most importantly, the evolution of the optical transmittance of the substrate has been monitored in situ in real time during the CVD growth using DTS. The formation of the MoS2 monolayers is clearly visible from the development of the DT spectrum. More

• specifically, the onset of the growth and the variation of the growth rate of MoS2 monolayers can be determined. This detailed information about the growth deduced from the DTS results can be correlated very well to the variation of the temperature of the substrate, the MoO3, and the sulfur sources. The

Quantification and coupling of the electromagnetic and chemical contributions in surface-enhanced Raman scattering

• Yarong Su,
• Yuanzhen Shi,
• Ping Wang,
• Jinglei Du,
• Markus B. Raschke and
• Lin Pang

Beilstein J. Nanotechnol. 2019, 10, 549–556, doi:10.3762/bjnano.10.56

• Raman active modes of benzenethiol on different substrates and when limited to within a fraction of the localized surface plasmon bandwidth. Representative Raman spectra of self-assembled monolayers of benzenethiol acquired on four different metal substrates, in comparison to neat benzenethiol are

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

• catalyst for further investigation of CO2 conversion due to its high selectivity and activation for CO2. The study shows that Mo-doped BN monolayers can be used as a promising catalyst for CO2 reduction to CH4 with a low limiting potential of −0.45 V. More importantly, Mo is an abundant element in the

• earth, thus using Mo-doped BN monolayers as an electrocatalyst for CO2 conversion can significantly reduce the cost compared with conventional noble-metal catalysts, such Au, Ag, Pt, Pd and so on [30][33][48][49]. This work provides insight and guidance to experimentalists in search of low cost, high

• onto BN monolayers (TM-doped BN) as the SACs, the interaction between CO2 and various TM (Sc to Zn, Mo, Ru, Rh, Pd and Ag) doped BN monolayers were considered. Moreover, for efficient reduction of CO2, the interaction between CO2 and the catalyst should be stronger than that between H2O and the

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

• versatile and convenient tool for modifying the material structure through a controlled induction of lattice defects, cutting or atom implantation [1][2][3]. This method is useful for engineering of the optical, electric and catalytic properties of monolayers [1][2][3]. For technical simplicity, ion

• , initially recognized due to its catalytic effect in the CVD synthesis of graphene. SiO2, the most common material for supporting monolayers (usually in the SiO2/Si alignment), is in turn a typical dielectric, mostly referred to as introducing a comparatively small effect on the properties of 2D materials

• . For the uniformity of the study, a classical semiconducting material SiC was added as another commonly used substrate. Al2O3 is also an insulator that is becoming a more interesting material to support monolayers given that is has a small effect on their properties; besides, comparing it to SiO2 is

One-step nonhydrolytic sol–gel synthesis of mesoporous TiO₂ phosphonate hybrid materials

• Yanhui Wang,
• P. Hubert Mutin and
• Johan G. Alauzun

Beilstein J. Nanotechnol. 2019, 10, 356–362, doi:10.3762/bjnano.10.35

• diameter of the crystallites (assuming a spherical shape and a density of 3.8), increases with the P/Ti ratio from 1.5 P/nm2 for TiP0.02 to 2.9 P/nm2 for TiP0.1. These values suggest the formation of monolayers with low to moderate density (grafting densities of up to 4 to 5 P/nm2 have been reported for

• well-ordered self-assembled monolayers). The mesoporosity of the hybrid materials with P/Ti ratios up to 0.1 stems from the aggregation of the grafted nanoparticles (interparticle porosity). The smaller the size of the particles, the higher the specific surface area and the lower the pore volume

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

• fully penetrate the monolayer. The latter problem could be solved by creating colloidal monolayers with a larger spacing, for example by optimizing the surface chemistry of particles. The mechanism of generating grip on the tested substrates is likely indentation-based, creating mechanical interlocking

• monolayers on glass using dip coating: Colloidal monolayers from sub-microscale and microscale particles were obtained by deposition of particles on an untreated microscopic slide of glass (75 × 26 mm2) (Corning®) using a dip coating process [45]. Specifically, a Langmuir–Blodgett trough (KSV Nima KN2002

• uncured PDMS of 1:10 and 1:20 crosslinker/pre-polymer weight ratios in a desiccator. Uncured PDMS was cast on a 14 × 14 mm2 area of an untreated microscopic glass to obtain a layer of 4 mm thickness, and subsequently cured in an oven for 2 h at 68 °C. Characterization of micropatterns Monolayers and