Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy

• Natalie Frese,
• Patrick Schmerer,
• Martin Wortmann,
• Matthias Schürmann,
• Matthias König,
• Michael Westphal,
• Friedemann Weber,
• Holger Sudhoff and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 172–179, doi:10.3762/bjnano.12.13

• biosafety level 3 conditions with enhanced respiratory personal protection equipment. For HIM, cells were seeded onto coverslips placed in 24-well plates. The coverslips were previously sputter coated with 30 nm of gold to improve charge neutralization during HIM imaging. After 24 h, nearly confluent

• fixation and critical point drying. As He+ ions can penetrate several hundred nanometers into the sample [29], the outer rim of the cells appears brighter because the ions pass through the cells and generate additional secondary electrons at the back of the cells and in the gold-coated specimen slide [30

• topography or material contrast. The deposited carbon film is presumably thinner than typical conductive metal or carbon coatings for SEM imaging, and it does not show any surface masking and clustering as seen on the gold substrate in the upper left of Figure 2b2. The energy of the incident hydrocarbons is

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• flexible conductive materials, metallic materials (e.g., copper, zinc, silver, and gold) are still frequently used as electrodes for flexible electronics due to their excellent electrical conductivity. By using the Kapton tape to attach soft stencils to paper, various metals can be deposited through the

Mapping the local dielectric constant of a biological nanostructured system

• Wescley Walison Valeriano,
• Rodrigo Ribeiro Andrade,
• Juan Pablo Vasco,
• Angelo Malachias,
• Bernardo Ruegger Almeida Neves,
• Paulo Sergio Soares Guimarães and
• Wagner Nunes Rodrigues

Beilstein J. Nanotechnol. 2021, 12, 139–150, doi:10.3762/bjnano.12.11

• and R = (42.6 ± 0.2) nm; and for the yellow/green region the parameters are f0 = 67.972 kHz, K = 2.18 N/m and R = (35.9 ± 0.2) nm. Similar to the case of Al2O3 (see Experimental section), the substrate region was set to εr = 1 since in this region there is only air between the probe and the gold

• measurements on a gold surface and determine the coefficient α. Over the gold surface, the effective thickness of the sample h goes to zero, thus h/εr = 0 [13][32], and Equation 6 can be seen as a function of R. The coefficient α depends on z and to obtain the correct value of R, it is necessary to perform the

• defined disks of Al2O3 films with a radius of 5 µm deposited by ALD on Au/Cr (60 nm/20 nm)-coated silicon wafer pieces. The topographic image of an Al2O3 disk measured with AFM is shown in Figure 9a. The sample thickness was (21.0 ± 0.2) nm, relative to the gold surface. In the EFM mode, the microscope

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• ] synthesized AgNPs in cylindrical matrices using TMV as the biotemplate. In this work, AgNPs were 2–4 nm in size and it was shown that AgNPs, unlike platinum and gold nanoparticles, were coated on the inner surface of the TMV channel. The synthesis process is known to be mediated by the amino acid functional

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• electrons (SPECS flood gun) in high vacuum (10−7 mbar) using doses of 50 mC/cm2. The cross-linking of a NBPT SAM on gold on mica leads to an NBPT CNM. Preparation of PM Frozen wild-type (WT) and c-His-tagged purple membrane were thawed, vortexed and subsequently diluted to the desired optical density (OD

• to 399.2 eV, by the broadening of the oxygen and carbon peak, and by additional sulfur species belonging to thiol groups no longer bound to gold after cross-linking. The presence of oxygen in the CNM spectrum is due to atmospheric contamination and can theoretically be avoided by preparation in high

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• = 687 µm, and thickness τ = 121 µm, are used in the finite element model. The arrangement of the gold electrodes on the tuning fork is the same as in reality. One electrode pair is grounded and the other is set to a virtual ground. The calculated mechanical eigenfrequency of the bare tuning fork is

• for quartz, gold, and tungsten were taken from the materials library of the simulation software, except for the damping coefficient for quartz, which was chosen based on our experimental results. According to [26], it is also worth noting that (i) due to the comparatively low internal damping

• occurring inside gold and tungsten, we did not assign a damping coefficient to any of these materials to reduce the computational cost, and that (ii) the sensor is oscillating in vacuum. Observation by scanning electron microscope (SEM) Firstly, in this paper, the whole assembly consisting of tuning fork

The role of gold atom concentration in the formation of Cu–Au nanoparticles from the gas phase

• Yuri Ya. Gafner,
• Svetlana L. Gafner,
• Darya A. Ryzkova and
• Andrey V. Nomoev

Beilstein J. Nanotechnol. 2021, 12, 72–81, doi:10.3762/bjnano.12.6

• concentration of gold atoms on the size and on the actual chemical composition of the formed bimetallic nanoparticles. The modeled region had a cubic shape with a face length of 1350 Bohr radii and contained a total of 91125 copper and gold atoms uniformly distributed in space. Thus, based on the results of the

• MD simulation, it was concluded that an increase in the percentage of gold atoms in the initial vapor phase led to a decrease in the size of the synthesized nanoparticles. In addition, it was found that clusters with a size of more than 400–500 atoms, regardless of the chemical composition of the

• initial vapor phase, basically corresponded to a given target composition. Keywords: binary nanoparticles; computer simulation; copper; gold; molecular dynamics; Introduction The nanometer-sized Cu–Au compounds are being studied quite actively [1][2][3][4][5][6][7][8] because of their potential

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• first author, Cynthia Kembuan, published as "Synthesis and characterization of gold shell nanoparticles for controlled enhancement of photon upconversion process" (Freie Universität Berlin, 2020). Funding This research was supported by the EU (COST Action 1403), the Deutsche Forschungsgemeinschaft (DFG

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• al. [12], fruit flies by Boseman et al. [13], and pine leaves by Kim [14] marked the entrance of HIM into general biology. Soon afterwards, two more milestones were reached. Firstly, Rice et al. [15] successfully imaged 15 nm gold labels on cell-surface proteins in rat kidneys, which demonstrated

• materials, such as carbon, platinum, or gold. Coating the samples can, however, result in minute changes to surface features which are only visible at very high resolution. One of the main advantages of HIM is the ability to neutralise charge by implementation of an electron flood gun. This flood gun

• study published in the same year, Bazou et al. employed HIM to image human colon cancer cells (Caco2) [9]. The glutaraldehyde-fixed and freeze-dried cells were imaged by both HIM and SEM to enable the direct comparison between the two instruments. HIM analysis of gold-coated and uncoated samples showed

Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

• Eduardo Serralta,
• Nico Klingner,
• Olivier De Castro,
• Michael Mousley,
• Santhana Eswara,
• Serge Duarte Pinto,
• Tom Wirtz and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2020, 11, 1854–1864, doi:10.3762/bjnano.11.167

• annular microchannel plate detector was used for investigating gold–silica core–shell nanoparticles in ADF mode [30]. These approaches require a physical aperture to restrict the acceptance angle when performed in BF, and a physical change of the distance between the sample and the annular detector to

• dioxide was deposited on one half, visible on the upper left half of the area in Figure 3a. Then, in the next step, a gold layer of 20 nm was deposited on the lower left half of the sample, creating four distinct areas on the window. The different material stacks are indicated in the STIM image. In Figure

• area on which only gold is deposited is stronger than expected while the signal on the area on which only silicon dioxide is deposited is weaker. A further study on the thickness of each layer using different techniques has not been performed, although deviations of the layer thickness could be

Electron beam-induced deposition of platinum from Pt(CO)₂Cl₂ and Pt(CO)₂Br₂

• Aya Mahgoub,
• Hang Lu,
• Rachel M. Thorman,
• Konstantin Preradovic,
• Titel Jurca,
• Lisa McElwee-White,
• Howard Fairbrother and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2020, 11, 1789–1800, doi:10.3762/bjnano.11.161

• carbon content. In this way, water has been used for the purification of FEBID of platinum [33][34] and gold [35]. An analogous reaction occurs with ammonia to get rid of the halogen in deposits from the (η3-C3H5)Ru(CO)3Cl precursor [36]. However, this reaction scheme would lead to a much lower carbon

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• ][29] was used. All milling experiments were performed on a 100 nm thin gold film on glass. For measuring the trench width milled into the gold layer, either the same primary ion beam microscope or a scanning electron microscope have been used to image the sputtered trenches. The investigated sources

• Yamamura et al. [34] are also given in Table 2. They are in a good agreement with the experimentally determined data from literature (volume-loss method), for example, for 30 keV helium in gold Yexp = 0.13 and for 35 keV lithium in gold Yexp = 0.4 [17]. Single-pixel lines have been milled with different

• analyzed for the full width of the profile at half height or corresponding trench depth (FWHM). The normalized expected trench profiles from a point-like beam in a gold substrate have been plotted for selected ion species in Figure 5. The beam profiles however, are not Gaussian and the edge profiles cannot

Oxidation of Au/Ag films by oxygen plasma: phase separation and generation of nanoporosity

• Abdel-Aziz El Mel,
• Said A. Mansour,
• Mujaheed Pasha,
• Atef Zekri,
• Janarthanan Ponraj,
• Akshath Shetty and
• Yousef Haik

Beilstein J. Nanotechnol. 2020, 11, 1608–1614, doi:10.3762/bjnano.11.143

• silver and gold. In addition, it was shown that the preferential oxidation of silver resulted in a solid-state diffusion of silver toward the surface where it oxidized and formed nanoporous microspheres. The gold phase remaining in the film exhibited nanoporosity due to the injected vacancies at the

• a fundamental point of view, gold/silver is a peculiar model system to study corrosion processes since gold is a noble metal. Interestingly, by using different types of Au/Ag nanoparticles, Lewis et al. showed how one can control and engineer, at the nanometer scale, the final shape and structure of

• gold/silver oxide nanostructures [20]. Starting from Au/Ag alloy nanospheres, they showed that gold/silver oxide core/shell nanospheres with a hollow interior could be obtained after oxidation using atomic oxygen. In this study we further explored the oxidation and phase separation events observed by

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• electrochemical method, three-dimensional arrayed nanopore structures are machined onto a Mg surface. The structured Mg surface is coated with a thin gold (Au) film, which is used as a surface-enhanced Raman scattering (SERS) substrate. A rhodamine 6G (R6G) probe molecule is used as the detection agent for the

• . Additionally, a 10−6 mol·L−1 solution of lysozyme was successfully detected using the Mg–Au nanopore substrates. Our low-cost method is reproducible, homogeneous, and suitable for the fabrication of SERS substrates. Keywords: electrochemical machining; gold (Au); lysozyme detection; magnesium (Mg); micro

• ] fabricated elliptical nanostructures and studied the effect of processing distance parameters and gold film thickness on the Raman intensity of R6G. They found that the Raman intensity of R6G was highest on densely packed structures. Additionally, the Raman intensity of R6G decreases as the number of hot

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• breaks down [39][40]. Here, several approaches to create low-cost, large-area SERS substrates that exhibit homogeneous Raman intensity enhancement are introduced. The substrates are based on quasi-hexagonally ordered gold particles prepared by block-copolymer micellar nanolithography and electroless

• deposition [41], or on dense silver island films created by pulsed laser deposition [42] or physical vapor deposition [43]. In [44], individual plasmonic nanotags are prepared by coating gold nanoparticle clusters with Raman reporters. This work explores the minimum number of tags required for obtaining a

• are on the lookout for nanotips that can be prepared fast and with reproducible properties, and at the same time, aim for ever higher field enhancement and localization to improve the sensitivity and spatial resolution of the TERS information. In [47], an earlier protocol for etching thin gold wires

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• dimensions, the optimum V-shaped cantilever that can provide the maximum phase contrast in bimodal AFM between gold (Au) and polystyrene (PS) is found. Based on this study, it is found that as the length of the cantilever increases the 2nd eigenmode phase contrast decreases. However, the base width exhibits

• geometries while interacting with polystyrene (PS) and gold (Au) surfaces in bimodal AFM. The tip–sample force interactions are categorized into long-range van der Waals forces and short-range forces described by the Derjaguin, Muller and Toporov (DMT) model. The instantaneous tip distance d is defined as d

• order to find the optimum geometry, the cantilever is modeled as a Timoshenko beam and is excited simultaneously by two fundamental bending modes as bimodal AFM. In each step, the optimum dimensional parameter yielding the highest material composition contrast between two samples of gold (Au) and

Helium ion microscope – secondary ion mass spectrometry for geological materials

• Matthew R. Ball,
• Richard J. M. Taylor,
• Joshua F. Einsle,
• Fouzia Khanom,
• Christelle Guillermier and
• Richard J. Harrison

Beilstein J. Nanotechnol. 2020, 11, 1504–1515, doi:10.3762/bjnano.11.133

• , typically gold, using a sputter coater. Here we employ a similar technique, coating samples with either gold or platinum, or, in the case of analysis of platinum-group elements [15], carbon. This coating is removed by the action of the primary beam in the region of interest prior to analysis, allowing for

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• diameters ranging between 80 and 180 nm and length values that can reach several tens of micrometers. The chemical reduction method was initially proposed by Michael Faraday in 1856–1857 while investigating the properties of colloidal gold. This method generally uses a precursor, a reducing agent, and a

• ]. Silver, gold, zinc oxide, and titanium dioxide NPs can be attracted to the cell wall by electrostatic attraction [161], van der Waals forces [162], and hydrophobic interactions [163], inducing changes in the shape, function and permeability of the cells. Proteins and DNA Proteins play a fundamental role

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• layer for the wet etching of silicon. The MACE process has been extensively studied over the last decade [13][14][15][16]. In theory, the process works with a wide range of noble metals. The main focus in research has been set on the noble metals gold (Au) and silver (Ag) [2][17][18][19]. Other studies

• nanoparticles and a poly(methyl methacrylate) (PMMA) patterning were etched in a diluted HF/H2O2 solution for 10 min. The process was a single-wafer bath process and can be scaled up to a batch process easily. As a reference, one wafer with gold nanoparticles was etched in a HF solution (1.73 mol/L) without the

• geometry of the self-assembled structures in a wide range. This includes high aspect ratio silicon nanowires (so-called black silicon) with an average reflectance of less than 0.5%. The etching mechanism can also be optimised by the selection of the noble metal. The usage of gold will lead to straight

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• al. studied how biomolecules influenced the stability of gold nanoparticles and showed that serum proteins at high concentrations stabilized the nanoparticles, whereas lower concentrations enhanced nanoparticle aggregation. Also, immunoglobulins and fibrinogen caused a greater extent of particle

Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

• theoretical, (ii) empirical, and (iii) semi-empirical models. The formation of nanometre-sized gold particles on silicon and silicon oxide substrates is investigated in detail. In addition, the strengths and weaknesses of the three models are elucidated, the different substrates used are compared, and the

• system due to material re-evaporation and Ostwald ripening describes the theoretically predicted and experimentally obtained results. Thus, dewetting phenomena of thin metal layers can be used to manufacture nanostructured devices. From this point of view, the application of gold droplets as catalysts to

• chalcopyrites [11], or precursors for complex structures, such as nanowires [12]. Silicon, germanium and silicon oxide nanowires, for example, can be formed on different substrates by using metal catalysts in the form of tin, indium or gold nanodroplets [13][14][15]. Such nanometre-sized one-dimensional

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• -probe geometry. Thus, the absolute values of μ extracted here (approx. 1 cm2 V−1 s−1) are limited by the contact resistance between the gold and the MoS2 [40]. We now consider the effect of irradiating the metal–semiconductor interface. We treated two FETs within each IR regime. For one of the devices

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• fate of this ligand is. In the catalysis study with MnTUPCl at the Au(111) surface, two possible mechanisms were proposed [7]: (i) A surface gold atom coordinates to the manganese center of MnTUPCl in an axial ligand-like fashion, inducing a chlorine radical to dissociate, thereby reducing the Mn(III

• mentioned in the introduction was the direct attachment of a gold atom to the manganese center of MnTUPCl, coming from the Au(111) surface below. As a first experiment we therefore decided to also investigate with STM the behavior of MnTUPCl at a HOPG surface instead of a Au(111) surface, since in that case

• forward two possible explanations for the reduction of the manganese centers of the molecules of MnTUPCl at the Au(111)–n-tetradecane interface in a liquid-STM, i.e., the coordination of a gold atom from the top-most gold layer to MnTUPCl in an axial ligand-like fashion, or an active reduction as the

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

• Dinesh Rotake,
• Anand Darji and
• Nitin Kale

Beilstein J. Nanotechnol. 2020, 11, 1242–1253, doi:10.3762/bjnano.11.108

• structure with thickness, FESEM image, PCB, and the experimental platform is shown in Figure 1. For using the microcantilever device for selectively detecting Cd(II) a surface modification is required. The surface modification of the sensor is basically a selective thiol coating on top of a gold surface

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• nanoparticles are due to the resonant oscillation of the surface electrons, called surface plasmons (e.g., plasmonic gold and silver nanoparticles) [38], or they are due to the energy of the band transitions (e.g., Cu2+ d–d transition in CuS nanoparticles) [39]. Under visible–NIR light irradiation, these

• photothermally active antibacterial nanoparticles found in the literature are shown in Figure 1. The outline of this review is summarized in Figure 2. Plasmonic gold nanoparticles for bacteria and biofilm photothermal ablation According to our literature search, gold nanoparticles in various dimensions and

• shapes are the most widely studied nanomaterial for the photothermal ablation of bacteria and biofilms. This may be explained by the fact that some of these gold nanoparticles are commercially available and are also widely applied in other fields of nanotechnology and nanomedicine. Therefore, the