Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• diameter of 299 ± 128 nm (Figure 1b). The particles were subsequently collected and suspended in media. After allowing the particles to equilibrate for 24 h, the average particle diameter value increased to 356 ± 190 nm according to dynamic light scattering (DLS) measurements. The size distribution curves

• hydrodynamic diameter values of 373 ± 180 nm and 356 ± 190 nm, respectively (Figure 2a). The zeta potential values (ζp) of the SPNPs were also measured via electrophoretic light scattering in the same suspension medium used in the EK experiments. The obtained results were −20.0 ± 0.6 mV for the SPNP-BSA-488

• the desired particles. Particles, in their dry state, were imaged using SEM for shape analysis. To determine their hydrodynamic size distribution after being hydrated, the particles were suspended in ultrapure H2O + 0.01% Tween 20, sonicated on ice, and measured with dynamic light scattering (Malvern

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

• . Prominent examples are SERS and TERS, where the intrinsically small Raman scattering cross-section is enhanced by several orders of magnitude, making single-molecule spectroscopy feasible. These spectroscopic techniques have shown tremendous progress in the last two decades [29][30][31][32]. Under high

• sizeable third-harmonic generation from the pillar. The fact that nonlinear effects can already be observed in the absorption and scattering of single gold nanoparticles at much lower laser intensities is demonstrated in [56]. Using the so-called x-scan technique, a nanoparticle is scanned through a

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

• analysed by Fazio et al. [1]. It is mainly based on multiple light scattering at the silicon nanowires. Figure 4 shows SEM images of an etched wafer using Au nanoparticles as etching catalyst. This wafer has been etched with 50 mmol/L H2O2 for 10 min. The SEM images show cross sections of the wafer centre

• significantly on the wafers. The process is quite homogeneous over the whole wafer. The straight etching profile indicates that the main etching occurred in the first etching regime (where n = 4). The top-view SEM image in Figure 4e has been acquired with increased electron energy. Using a back-scattering

• is caused by multiple light scattering and reflection within the nanostructures [1]. The wafers etched with a higher H2O2 concentration show a lower mean reflectance. This lower reflectance is correlated to the increased etching depth with increasing H2O2 concentration. All these wafers contain

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

• diameter Di. The dispersity (Ð) is expressed by the ratio Dw/Dn, where Dw is the weight-average particle diameter, Dw = ΣNiDi4/ΣNiDi3. The hydrodynamic diameter Dh (z-average) and polydispersity index (PI) as measures of the distribution width were obtained by dynamic light scattering (DLS) with a

• concentrations was considered as 100% in further calculations. Analysis of the size of γ-Fe2O3 nanoparticles in different media by laser correlation spectroscopy The size of γ-Fe2O3 nanoparticles was measured by dynamic light scattering using a laser correlation spectrometer ZetaSizer-3 (Malvern Instrument, UK

• from 1 nm to 50 µm. Registration and statistical processing of laser light scattered by a water (n = 1.33) suspension of the nanoparticles, measured repeatedly for 120 s at 22 °С at a scattering angle of 90°, were carried out. The results of the experiments were processed using the software PCS-Size

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• ][29]. PFP, in contrast, exhibits π-stacking on various substrates [18][56]. The X-ray scattering data shown in Supporting Information File 1, Figure S7 confirmed this ordering motif for the Ag(111) surface. The almost symmetric shape of the PFP HOMO in multilayers on Ag(111) resembled that of likewise

Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

• Sergey Bakurskiy,
• Mikhail Kupriyanov,
• Nikolay V. Klenov,
• Igor Soloviev,
• Andrey Schegolev,
• Roman Morari,
• Yury Khaydukov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1336–1345, doi:10.3762/bjnano.11.118

• enhancement of the effective exchange field in this artificial ferromagnet. Previously, the properties of [Co(1.5 nm)/Nb(8 nm)/Co(2.5 nm)/Nb(8 nm)]6 multilayer structures for cryogenic memory applications were studied using polarized neutron scattering and magnetometry techniques [9]. In particular, the

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

• improvement of both the carrier mobility in the transistor channel and the electrical conductance of the MoS2, due to doping with ion beam-created sulfur vacancies. Larger areal irradiations introduce a higher concentration of scattering centers, hampering the electrical performance of the device. In addition

• creation of defects in TMD FETs may serve to improve charge transport and tune the device performance [10][20][28], while the effective donor concentration and the introduced scattering potentials need to be tailored accordingly [29][30]. Thus far, these studies have focused either on spatially confined

• region of the transfer curve, μ is seen to improve by up to 40% in two out of three devices in the blue region. For the green and red regions of IR, μ is always seen to worsen as the area of the irradiated channel is increased. μ is expected to drop heavily as the rate of electron scattering rises with

Proximity effect in [Nb(1.5 nm)/Fe(x)]₁₀/Nb(50 nm) superconductor/ferromagnet heterostructures

• Yury Khaydukov,
• Sabine Pütter,
• Laura Guasco,
• Roman Morari,
• Gideok Kim,
• Thomas Keller,
• Anatolie Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2020, 11, 1254–1263, doi:10.3762/bjnano.11.109

• the reflectivity is proportional to the square of the Fourier transform of dρ(z)/dz, where ρ(z) is the depth profile of the scattering length density (SLD). The SLD is defined as the product of the averaged scattering length and the density N. For a periodic structure with period D repeated n times

• between the SLDs of Fe and Nb. Interdiffusion will lead to suppression of the contrast and, hence, of R1. Assuming that the packing density Nav is the same for both layers, we may estimate the concentration of Fe in the FecNb1−c alloy as where = ρ/Nav is the averaged coherent scattering length of the

• corresponding layer, and bFe and bNb are the coherent scattering lengths of Fe and Nb. The X-ray SLDs of Fe and Nb differ only by a few percent, which makes the X-ray contrast very small even without interdiffusion. For neutrons, in contrast, the SLDs of Fe and Nb, ρFe = 8 × 10−4 nm−2 and ρNb = 3.9 × 10−4 nm−2

Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• reference sample (20–50 nm). It is well known that distinguishing between magnetite (Fe3O4) and maghemite (γ-Fe2O3) only using the diffraction technique is not straightforward. However, these samples can be easily distinguished by Raman scattering, since Fe3O4, γ-Fe2O3 and other iron oxides and hydroxides

• to excite the Raman scattering. The irradiation power density on the sample was continuously decreased (using neutral density filters and beam defocusing) until no further changes were observed in the obtained spectra. A power of ≈0.2 mW on the sample and a laser spot diameter of ≈30 μm were

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• relatively large Ga+ beam diameter (approx. 5 nm) and a high proximity effect generated by Ga+ ion scattering. Regarding a higher spatial resolution, the helium ion microscope (HIM) [27], based on a gas field-ionization source, has emerged as a tool for direct writing of complex 3D nano-objects taking

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

• microscopy images. Additionally, the polarizations of Raman scattering and the photoluminescence signal from the tip–sample nanogap are explored by combining polarization angle-resolved emission spectroscopy with tip-enhanced optical spectroscopy. Our work demonstrates the significant potential of resolving

• polarizations of Raman scattering and the photoluminescence from the tip–sample nanogap. Results and Discussion Silicon nanowire core–shell morphology In accordance with the VLS synthesis method (see Experimental section), the utilized Pt catalyst, or finally PtxSiy, remains at the tip of the nanowire during

• ratio between the crystalline Si and amorphous Si Raman peaks at sample positions as close as eight nanometers can be revealed. Furthermore, the polarizations of Raman scattering and photoluminescence signals locally emitted from a single SiNW are explored by combining polarization angle-resolved

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• , these devices are tunable by varying the neck width. A4Z6-6 exhibits a large current in comparison with A4Z6-24. This is attributed to an increase in the amount of defects in A4Z6-24, i.e., the increasing scattering of carriers decreases the transmission. Another reason is the size of the bandgap

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

• -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

• -estradiol, an emerging contaminant in environmental waters. We have found a limit of detection of 1 nM with a sensitivity allowing for a dynamic range of five orders of magnitude (up to 100 µM). Keywords: aptamer; Au nanoparticles; 17-β estradiol (E2); plasmonics; sensor; surface-enhanced Raman scattering

• (SERS); TiO2 nanostructures; Introduction Surface-enhanced Raman scattering (SERS) as a sensing tool requires the optimization of a surface and its functionalization. The surface should provide a good enhancement over a large range of wavelengths, to detect molecules with various fingerprints, while it

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

• the IOPs were homogeneously embedded as micrometer-sized agglomerates in the chitosan matrix (Figure 3B,C). Individual IOPs had a diameter of approximately 100 nm whereas their aggregates had a diameter on the order of several micrometers. According to the dynamic light scattering results (Table S2

• IOP dispersions in 1% acetic acid using a dynamic light scattering device (ZetaSizer NanoSP, Malvern, United Kingdom). Preparation of chitosan microfibers with IOPs A coagulation bath containing absolute ethanol (VWR, Darmstadt, Germany) was prepared in a polyethylene terephthalate glycol tube (MOCAP

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• , the results showed that films are deposited with wurtzite structure as the dominant phase even after phase segregation in the investigated Mg concentration interval. The issue of phase segregation was also investigated via selective resonant Raman scattering in a wider composition range of x = 0.00

• about 400 meV. One can see from Figure 4 and Figure 5 that narrow emission lines related to resonance Raman scattering (RRS) are present in the emission spectrum from the ZnMgO films in addition to the broad PL bands, which is indicative of the high optical properties of the films produced by sol–gel

• summarized PL band maximum in Zn1−xMgxO films. The conditions of resonance Raman scattering in ZnMgO films for various compositions and temperatures. Funding The following sources of funding are acknowledged: National Agency for Research and Development of the Republic of Moldova (Grant No

Simulations of the 2D self-assembly of tripod-shaped building blocks

• Łukasz Baran,
• Wojciech Rżysko and
• Edyta Słyk

Beilstein J. Nanotechnol. 2020, 11, 884–890, doi:10.3762/bjnano.11.73

• structure factors with respect to the central segment. Nasso takes values from 0 to 6, where 0 means that no molecules have interacted and 6 means that all molecules are associated. The structure factor shows the symmetry of the obtained functions. This parameter corresponds to the neutron scattering

A Josephson junction based on a highly disordered superconductor/low-resistivity normal metal bilayer

• Pavel M. Marychev and
• Denis Yu. Vodolazov

Beilstein J. Nanotechnol. 2020, 11, 858–865, doi:10.3762/bjnano.11.71

• ) is the ratio between electron and phonon heat capacity at T = Tc0 and τ0 determines the strength of electron–phonon inelastic scattering in the S and the N layer (see Equations 4 and 6 in [25]). For τ0 we use the smallest time for S and N materials due to the assumably good transfer of electrons

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• exceeding −0.01 dB·cm−1. The underlying relation of bend loss versus bend radius was obtained from simulations. The estimated scattering loss at each Y-splitter is −0.5 dB. The intrinsic waveguide propagation loss for the chosen width and thickness is −0.5 dB∙cm−1. For the waveguide lengths used, the

• of the 16-waveguide device actuated by 785 nm laser light. As a result of light scattering, both the excitation and the detection waveguides light up. A further indication of the operation of the detection waveguide is the bright spot at the chip edge indicated with the number 5. Experimental setup

• perpendicular to the plane of the chip. We optimize the fiber-to-waveguide coupling by maximizing the lighting up of the waveguide circuitry. This lighting up results from scattering of the propagating waveguide modes and can be monitored using an air objective and a camera mountable above the chip. The light

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• ) film can be easily identified. The significant peak broadening of the diffraction maxima of VN and Pd0.96Fe0.04 is primarily due to small coherent scattering range τ along the normal to the film plane (Scherrer broadening); XRD data with accounting for the instrument function [33] yields estimates of τ

• R(T) behavior of VN/MgO(011) samples in [42], which was explained by a change in the electron/phonon scattering amplitude upon the structural phase transition from cubic to tetragonal at Ts = 250 K. Below 50 K the R(T) dependence saturates approaching the residual resistance originating, in general

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• exhibit damping, and thus the FWHM of the Raman peaks have a finite width, indicating the presence of decay channels that reduce τ. In general, the phonon linewidths contain contributions arising from several scattering mechanisms such as the electron–electron interaction, i.e., Coulombic scattering, or

• the electron–phonon interaction, i.e., scattering of electrons from defects. Chakrabarty et al. reported that the linewidth of the A1g peak in single-layer MoS2 that was subsequently used in transistors, broadened due to n-type doping where the phonon linewidth renormalized under the presence of an

• electric filed [18]. Similarly, the Raman linewidths in graphene are found to increase with defects resulting from electron–impurity and electron–phonon scattering [19]. Moreover, the Raman linewidth broadening is also attributed to the confinement of the optical phonons. Specifically, in the case of low

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

• means, such as optical reflectance and absorption, electron energy loss spectroscopy, X-ray absorption, emission, and inelastic scattering. Regarding luminescence studies, PL is the light emission, i.e., the electromagnetic radiation from matter after the absorption of photons. It is originated by

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• ], localized surface plasmon resonance (LSPR) [25], and plasma excitation light scattering [26][27]. Cushing et al. [28] used the time-resolved method to track these three processes by establishing a density matrix model, which allowed them to predict the theoretical maximum catalytic efficiency and

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• roughness is attributed to the increasing grain sizes [35]. The large grain sizes of IAAI films reduce the number of grain boundaries and thus the scattering at grain boundaries. This improves the carrier mobility leading to an increased electrical conductivity of the films. The surface morphology of the

• less light scattering in the metal interlayer [28][29][30]. The annealing treatment has successfully reduced the number of defects leading light scattering [4][36]. The enhanced structural ordering decreases the electron scattering at grain boundaries and impurities. This can lead to an increase in the

• . Generally, the inclusion of low-resistivity metal thin films, coupled with a reduction in grain boundary scattering after annealing, is responsible for the large reduction in both sheet resistance and resistivity. Moreover, the optoelectronic properties of the IAAI films are better compared to those in the

Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

• Majid Sanaeepur

Beilstein J. Nanotechnol. 2020, 11, 688–694, doi:10.3762/bjnano.11.56

• Table 1 [37]. In nonequilibrium Green’s functions the retarded Green’s function of the device (scattering region) is written as [38]: where η is an infinitesimal positive number and the non-Hermitian self-energy matrix, Σ(E) = Σ1(E) + Σ2(E), represents the escape rate of electrons from the device into

Electromigration-induced directional steps towards the formation of single atomic Ag contacts

• Atasi Chatterjee,
• Christoph Tegenkamp and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2020, 11, 680–687, doi:10.3762/bjnano.11.55

• high probability of electron scattering at grain boundaries, material transport mainly happens at and across grain boundaries, but not within the homogeneous crystalline material that is typically assumed in most models. Therefore, deviations from these models must be expected. Focussing for the moment