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

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• gold tip. We positioned a Glan–Taylor polarizer in the beam in front of the entrance slit of the spectrometer and collected spectra while rotating the polarizer. The Glan–Taylor prism only transmits the optical signal along its fast axis. Therefore, the angle-resolved polarization of the emitted signal

• approaching the gold tip to the SiNW, the angle-resolved polarization pattern changes from a circular pattern (Figure 4c) to a more structured shape in Figure 6d. It is likely that the high refractive index of the SiNW has a certain impact on the polarization of the photoluminescence emitted from the narrow

• gap between the gold tip and the SiNW. A more quantitative investigation of the polarization angle-resolved emission patterns in Figure 6 will be further pursued. The results shown in Figure 4 and Figure 6 demonstrate that it is possible to combine the polarization angle-resolved experiments with a

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

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• 7314, 33 rue St Leu, 80039 Amiens cedex 1, France 10.3762/bjnano.11.95 Abstract A small water-soluble phosphorus-containing dendrimer was engineered for the complexation of gold(I) and for its reduction under mild conditions. Gold nanoparticles were obtained as colloidal suspensions simply and only

• when the powdered form of this dendrimer was dissolved in water, as shown by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses. The dendrimers acted simultaneously as mild reducers and as nanoreactors, favoring the self-assembly of gold atoms and promoting

• the growth and stabilization of isolated gold nanoparticles. Thus, an unprecedented method for the synthesis of colloidal suspensions of water-soluble gold nanoparticles was proposed in this work. Keywords: colloidal suspension; complexation; dendrimer; gold nanoparticle; phosphorus; Introduction

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• microscopy (EM), iron oxide magnetic beads for the separation of cells and molecules, gold and silver nanoparticles as fiducials for EM, for immuno-EM labeling and surface-enhanced Raman spectroscopy, or for gene transfection, liposomes for drug delivery, and gadolinium or iron oxide nanoparticles for

• of iron oxides in the form of magnetite (Fe3O4) or maghemite (Fe2O3) and are easy to produce through a few well-documented synthesis methods yielding different forms and structures (e.g., round, cubic, hexagonal, clusters, core–shell with gold, silica, polymers, or surfactants). A lot of research is

• the cell divides [111]. Another study compared the endocytosis of gold and iron oxide nanoparticles in a co-exposure experiment. The authors found that the cells are not selective and internalize nanoparticles of both types. However, they found that the co-exposure induces more endocytosis events than

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• samples was analyzed by SEM using a Carl Zeiss scanning microscope, model EVO 50. The sample was supported on the sample holder by dispersion of the powder on conductive double-sided adhesive tape. The samples were gold-coated before the measurements using a Sputter BAL-TEC, MED 0.50. Mass-coupled thermal

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• Procédés et des Matériaux (LSPM), CNRS, Université Sorbonne Paris Nord, 93430, Villetaneuse, France CSPBAT, UMR 7244, Université Sorbonne Paris Nord, 93430 Villetaneuse, France 10.3762/bjnano.11.87 Abstract We propose the use of gold nanoparticles grown on the surface of nanoporous TiO2 films as surface

• -enhanced Raman scattering (SERS) sensors for the detection of 17β-estradiol. Gold deposition on top of a TiO2 surface leads to the formation of nanoparticles the plasmonic properties of which fulfil the requirements of a SERS sensor. The morphological and optical properties of the surface were investigated

• , 0.1 M of NaCl and 5 mM of MgCl2, pH 7.5). The samples were left for 2 h in this solution before rinsing with Tris-HCl buffer solution and Milli-Q water. In order to prevent unspecific interactions between E2 and the gold surface, the sample was then left for 2 h in a solution of the blocking agent MCH

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• the high-vacuum deposition technique in order to grow Te nanotubes on silicon substrates containing previously deposited nanoparticles of silver or gold [22]. In both cases, 50 nm diameter Te nanotubes were obtained. When exposed to low concentrations of different toxic gases, including NO2, the Te

• performed using a DRONE–YM1 (Burevestnik, Russia) diffractometer with Fe Kα radiation. The rotational velocity of the scintillation counter was set to be either 2 or 4°/min. For the electrical and gas-sensing characterization, the samples were supplied with symmetrical gold or platinum electrodes

• , identified in our preliminary works as ohmics [25][26], which form electrically transparent contacts with Te. The gold or copper wires were then attached to the electrodes with a silver paste. Figure 1A shows the surface morphology of a Te film grown on a Pyrex glass substrate at a rate of 10 nm/s. As shown

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• scanning electron microscope (SEM) using a Zeiss Supra 40 field-emission device (Carl Zeiss, Oberkochen, Germany) at an acceleration voltage of 3 kV. Prior to SEM analysis, dried fibers were sputter-coated with a 7 nm gold layer using a Bal-Tec SCD 005 sputter system (Leica Microsystems, Wetzlar, Germany

Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• factors needs to be taken into account when developing a carrier system for this purpose. Depending on the chosen pathway to cross the BBB, nanoparticle material, size and surface properties such as functionalization and charge should be tailored to fit the specific route of BBB crossing. Keywords: gold

• , nanoparticles are considered as solid colloidal particles with a size between 1 and 1000 nm [23]. They can be produced from a variety of different materials including polymers, lipids or inorganic materials such gold or iron oxide [21]. The first reported nanoparticles able to pass the BBB were poly(butyl

• (e.g., human serum albumin) [28], gold nanoparticles [29] and superparamagnetic iron oxide nanoparticles [30]. This review aims to summarize (i) the different pathways to cross the BBB, (ii) the strategies that can be employed to increase nanoparticle BBB permeation without disrupting the BBB, as well

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• volumetric flow leads to a higher species dilution. Based on our numerical results, we were able to successfully grow laterally aligned SnO2 nanowires out of gold film edges and gold nanoparticles on a-plane sapphire substrates. In our experiments a horizontal 2-zone tube furnace was used. The generation of

• substrates were prepared by two different preparation methods for the catalyst seeds, which are required for the VLS process. As a catalyst material, gold was chosen. First, a-plane sapphire substrates with structured gold thin films (thickness 5 nm) by metal evaporation, and second, a-plane sapphire

• substrates covered with gold nanoparticles (Au NPs) were prepared. For the latter method, the substrates were cleaned with deionized (DI) water and dried with nitrogen before coating them with 10 µL of a 1:2 v/v% solution of Au NPs (80 nm gold nanospheres, citrate NanoXact 0.05 mg/mL, nanoComposix) and

A set of empirical equations describing the observed colours of metal–anodic aluminium oxide–Al nanostructures

• Cristina V. Manzano,
• Jakob J. Schwiedrzik,
• Gerhard Bürki,
• Laszlo Pethö,
• Johann Michler and
• Laetitia Philippe

Beilstein J. Nanotechnol. 2020, 11, 798–806, doi:10.3762/bjnano.11.64

• . The model proposed in this study was defined for two different metals, chromium and gold. The work reported in this manuscript provides a mathematical model to estimate the xy values in the CIE 1931 colour diagram by only measuring the thickness and porosity of the AAO films. Results and Discussion

• Alliance-Concept DP 650 DC magnetron sputtering equipment. 25, 17.5 and 10 nm thin films of gold were deposited on top of the AAO films using a Leica EM ACE600 sputtering equipment. The Au layers were deposited using a sputtering pressure and intensity of 5 × 10−2 mbar and 30 mA, respectively, and the Cr

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• at room temperature. In the case of SNPs, the samples were sputter-coated with a thick gold film (≈17 nm) under argon atmosphere to improve secondary electron emission during SEM imaging. The NPs morphology was observed at an acceleration voltage of 20 kV. Dynamic light scattering (DLS) The mean

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• , semiconductor quantum dots suffer from toxicity and are susceptible to oxidation. In this context, atomically precise gold nanoclusters protected by thiol monolayers have emerged as a new class of luminescent nanomaterials. Low toxicity, bioavailability, photostability as well as tunable size, composition, and

• optoelectronic properties make them suitable for bioimaging and biosensing applications. In this review, an overview of the sensing of pathogens, and of in vitro and in vivo bioimaging using luminescent gold nanoclusters along with the limitations with selected examples are discussed. Keywords: bioimaging

• ; biosensing; gold nanoclusters; immunoassay; luminescence; self-assembly; theranostics; Introduction Imaging methods play a central role in understanding the structural and functional biological processes of biomolecules, cells, tissues, organs, and even entire living organisms [1][2]. The importance of

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• within the PAH/DS capsule. The rupture and deformation of the capsules occurred via the formation of pores on the surface after laser irradiation at 530 nm (Figure 5c). The encapsulation of silver, gold and iron oxide NPs has been the most common in most of the studies [80][82][83][84]. The incorporation

• cell line showed a rapid uptake, demonstrating the potential for cancer therapy. Silica and gold NPs were assembled in a one pot assembly of specifically tailored diblock polymers of PLL and poly-ʟ-cysteine [82]. The electrostatic binding between the positively charged lysine blocks and negatively

• charged silica NPs as well as the disulfide linkages between cysteine blocks and gold NPs resulted in two types of functionalities in the capsule. In a similar way, the capsules incorporated with noble metal NPs (e.g., gold and silver) respond to external light illumination by increased surface plasmon