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

• University, Albert-Einstein-Allee 11, 89069 Ulm, Germany 10.3762/bjnano.11.107 Abstract The synthesis of magnetite (Fe3O4) nanorods using reverse co-precipitation of Fe3+ and Fe2+ ions in the presence of a static magnetic field is reported in this work. The phase composition and crystal structure of the

• the dipole–dipole interaction between their building blocks (small hexagonal faceted magnetite nanocrystals), which are formed during the first step of the reaction. The study suggests a facile, green and controllable method for synthesizing anisotropic magnetic nanoparticles in the absence of

• stabilizers, which is important for further modification of their surfaces and/or incorporation of the nanoparticles into different media. Keywords: anisotropic nanoparticles; magnetic nanoparticles; magnetite; nanorods; transmission electron microscopy; Introduction The research field dedicated to the

Influence of the magnetic nanoparticle coating on the magnetic relaxation time

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2020, 11, 1207–1216, doi:10.3762/bjnano.11.105

• nanoparticle coating plays an important role in the nanoparticle dispersion stability and biocompatibility. However, theoretical studies in this field are lacking. In addition, the ways in which the nanoparticle coating influences the magnetic properties of the nanoparticles are not yet understood. In order to

• fill in this gap, this study presents a numerical simulation model that elucidates how the nanoparticle coating affects the nanoparticle agglomeration tendency as well as the effective magnetic relaxation time of the system. To simulate the self-organization of the colloidal nanoparticles, a stochastic

• Langevin dynamics method was applied based on the effective Verlet-type algorithm. The Néel magnetic relaxation time was obtained via the Coffey method in an oblique magnetic field, adapted to the local magnetic field on a nanoparticle. Keywords: colloidal system; effective Verlet-type algorithm; magnetic

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

• is present along the whole nanowire length. Moreover, these nanowires become superconducting at 6.8 K and show high values of critical magnetic field and critical current density. Consequently, these 3D nano-objects could be implemented as components in the next generation of electronics, such as

• carriers of electric current and provide macroscopic, and thus robust, quantum coherence. This allows for a wide range of applications, particularly at the nanometer-scale, where they can be easily integrated in circuits and used as ultrasensitive sensors of magnetic fields, temperature and as key elements

• magnetic field (µ0Hc2(0)) up to 9.5 T [14][15][16]. Alternatively, in combination with Nb(NMe2)3(N-t-Bu), Ga+ FIBID yielded NbC wires with a broadened Tc range from 4 to 11 K [18]. One significant limitation is that 3D elements below 100 nm in diameter cannot be obtained with Ga+ FIBID, mainly due to the

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

• Kamila A. Szewczyk,
• Izabela A. Domagalska,
• Artur P. Durajski and
• Radosław Szczęśniak

Beilstein J. Nanotechnol. 2020, 11, 1178–1189, doi:10.3762/bjnano.11.102

• superconductors under high magnetic fields [74]. Unfortunately, due to enormous mathematical difficulties, their full self-consistent solutions are still unknown (Δn,k and Zn,k). Also, Freericks’ equations have been recently successfully used to analyze the superconducting state with high critical temperature

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

• irradiated gold nanocrosses attached to the bacteria was effective in eliminating and preventing bacterial regrowth. By combining the magnetic and optical properties of Fe3O4 and gold nanoparticles, respectively, multifunctional nanohybrids based on Fe3O4@Au (i.e., magnetite nanoparticles decorated with gold

• nanoparticles with a magnetic Fe3O4 shell, displaying strong magnetic responsiveness and tunable plasmonic properties (absorption maximum in the 480–825 nm range), were prepared as a multifunctional tool for bacterial disinfection [72]. The prepared nanoparticles displayed enhanced photothermal stability, high

• magnetic recyclability and low cytotoxicity. It was shown that even at low concentration (25 ppm) the nanoparticles could kill 100% of the E. coli (107 CFU mL−1) within 10 min upon NIR irradiation at 808 nm and 2 W/cm2 laser intensity. The possibility to exploit the biocompatible and FDA-approved Prussian

Gram-scale synthesis of splat-shaped Ag–TiO₂ nanocomposites for enhanced antimicrobial properties

• Mohammad Jaber,
• Asim Mushtaq,
• Kebiao Zhang,
• Jindan Wu,
• Dandan Luo,
• Zihan Yi,
• M. Zubair Iqbal and
• Xiangdong Kong

Beilstein J. Nanotechnol. 2020, 11, 1119–1125, doi:10.3762/bjnano.11.96

• under magnetic stirring for 2 h until all the reagents were completely dissolved. The reaction mixtures were transferred to a 100 mL polytetrafluoroethylene lining tube, placed in an autoclave and heated at 200 °C for 8 h. After the reaction was completed, the obtained material was washed three times

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

• to the P=S group in the 31P nuclear magnetic resonance (NMR) spectra (Figure 1 and Table 1). Indeed, this signal shifted from 52.1 ppm in 1 to 33.7 ppm in 2 (Δδ = −18.4 ppm). The attempts to generate the gold nanoparticles from compound 2 were carried out by adding water. This compound was not very

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

• magnetic resonance imaging (MRI) (for more on this topic consult [11][12][13][14]). Among the abovementioned nanoscience products, iron oxide nanoparticles, especially superparamagnetic iron oxide nanoparticles (SPIONs) hold a lot of promise in many domains, not only regarding biology [15]. SPIONs consist

• behave like one magnetic unit, rotating in the presence of a magnetic field without retaining the magnetism after the magnetic field is removed [17]. This property makes SPIONs good candidates for MRI, and also for a type of thermic treatment of cancer, called localized hyperthermia. There are also other

Vibration analysis and pull-in instability behavior in a multiwalled piezoelectric nanosensor with fluid flow conveyance

• Sayyid H. Hashemi Kachapi

Beilstein J. Nanotechnol. 2020, 11, 1072–1081, doi:10.3762/bjnano.11.92

• stress theory to investigate the effects of various fluid parameters on the pull-in voltage of carbon nanotubes conveying viscous fluid [15]. Also, the vibration analysis of viscoelastic double-walled carbon nanotubes (DWCNTs) combined with ZnO layers and subjected to magnetic and electric fields were

Uniform Fe₃O₄/Gd₂O₃-DHCA nanocubes for dual-mode magnetic resonance imaging

• Miao Qin,
• Yueyou Peng,
• Mengjie Xu,
• Hui Yan,
• Yizhu Cheng,
• Xiumei Zhang,
• Di Huang,
• Weiyi Chen and
• Yanfeng Meng

Beilstein J. Nanotechnol. 2020, 11, 1000–1009, doi:10.3762/bjnano.11.84

• multimodal magnetic resonance imaging (MRI) technique has been extensively studied over the past few years since it offers complementary information that can increase diagnostic accuracy. Simple methods to synthesize contrast agents are necessary for the development of multimodal MRI. Herein, uniformly

• -dihydroxyhydrocinnamic acid (DHCA); dual-mode imaging; Fe3O4/Gd2O3-DHCA nanocubes; gadolinium oxide (Gd2O3); iron(II,III) oxide (Fe3O4); magnetic resonance imaging (MRI); Introduction Magnetic resonance imaging (MRI) is a noninvasive technique that has been broadly used in the clinical field to assist in disease

• 1617 cm−1, corresponding to the benzene ring stretching vibration, which indicates that DHCA successfully modified the FGDA nanocubes. In order to verify the magnetic properties of FGDA nanocubes, the field-dependent magnetization (M–H) curves (Figure 2j) were obtained from the physical property

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

• biotechnological and tissue engineering applications. However, there are only a few methods available for the production of biocompatible helical microfibers. Given that, we present here a simple technique for the fabrication of helical chitosan microfibers with embedded magnetic nanoparticles. Composite fibers

• were prepared by wet-spinning and coagulation in an ethanol bath. Thereby, no toxic components were introduced into the wet-spun chitosan fibers. After drying, the helical fibers had a diameter of approximately 130 µm. Scanning electron microscopy analysis of wet-spun helices revealed that the magnetic

• helical chitosan microfibers exhibited an average Young’s modulus of 14 MPa. By taking advantage of the magnetic properties of the feedstock solution, the production of the helical fibers could be automated. The fabrication of the helical fibers was achieved by utilizing the magnetic properties of the

Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

• Santoshi Misra and
• Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

• the influence of varied dimensionless parameters has been the focus of research in contemporary times. This work models the effect of magnetic field, heat generation and absorption parameter in a steady, laminar, two-dimensional boundary layer flow of a nanofluid over a permeable stretching sheet at a

• –corrector method is employed to solve the equations. The impact of the dimensionless parameters, including the Brownian motion, thermophoresis, magnetic field, heat generation and absorption parameters, on the velocity, temperature and nanoparticle concentration of fluid flow are analysed systematically

• . Keywords: Brownian motion; heat generation and absorption; magnetic field; nanofluid; thermophoresis; Introduction The study of magnetohydrodynamic problems, such as nanofluid flow over a permeable stretching sheet, has recently become relevant due to potential applications in various fields of science

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

• ) are based on magnetite (Fe3O4) or maghemite (γ-Fe2O3) molecules encapsulated in polysaccharides, synthetic polymers or monomer coatings and have a size range from 1 to 100 nm [21][182]. SPIONs possess interesting magnetic properties and some formulations have already been approved as MRI contrast

• EGF were tested as contrast agent in an intracranial rat glioma model [30]. Functionalized SPIONs were able to cross the tumor BBB and to accumulate in the tumor and demonstrated high magnetic resonance contrast potential, confirming the ability of functionalized SPIONs to act as a diagnostic agent

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

• NbN/Al, NbN/Ag and MoN/Ag bilayers. Namely, the suppression of the critical temperature of the SN bilayer is smaller while the change in magnetic field penetration depth of the SN bilayer is larger than the Usadel model predicts. Therefore, the present results should be considered only as a route for

• Equation 12). SN-S-SN junctions made of a NbN/Al bilayer have been fabricated recently [26] and indications of the Josephson effect (the presence of Shapiro steps and a Fraunhofer-like dependence of the critical current on the magnetic field) have been observed. But due to not optimized parameters (dS = dc

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

• operation of the waveguides at 785 nm for the transverse magnetic (TM) polarization. For TM polarization, the electric field vector of the waveguide mode is directed perpendicular to the plane of the waveguide (the x–y plane, as indicated in Figure 1). This polarization is conserved in the emitted beam

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

• structure. We propose epitaxial single-crystalline thin films of VN and heteroepitaxial Pd1−xFex/VN and VN/Pd1−xFex (x ≤ 0.08) structures grown on MgO(001) as the materials of a choice for the improvement of superconducting magnetic random access memory characteristics. Keywords: epitaxial growth

• junction technology is currently implied to be used for the logics fabrication, however, hybrid Josephson junctions incorporating magnetic components are also considered for the mainframe computation components [9][14][15][16][17][18][19], and cache and main memories [8][20][21][22][23][24][25]. It is

• argued that the use of magnetic Josephson junctions in single-flux quantum electronics significantly reduces the number of junctions and interconnects in the circuits [26] and also has other important advantages such as wide operation margins and low bit-error rate [27]. The magnetic material has to be

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

• ) characterization and generation using ions, electrons or other irradiation methods, the observation of ensemble paramagnetic properties and their optically detected magnetic resonance by applying a high magnetic field until the isolation of single defects and eventually their optical spin coherent control. Weber

Observation of unexpected uniaxial magnetic anisotropy in La_2/3Sr_1/3MnO₃ films by a BaTiO₃ overlayer in an artificial multiferroic bilayer

• John E. Ordóñez,
• Lorena Marín,
• Luis A. Rodríguez,
• Pedro A. Algarabel,
• José A. Pardo,
• Roger Guzmán,
• Luis Morellón,
• César Magén,
• Etienne Snoeck,
• María E. Gómez and
• Manuel R. Ibarra

Beilstein J. Nanotechnol. 2020, 11, 651–661, doi:10.3762/bjnano.11.51

• , Universidad de Zaragoza, 50018 Zaragoza, Spain 10.3762/bjnano.11.51 Abstract We studied in detail the in-plane magnetic properties of heterostructures based on a ferroelectric BaTiO3 overlayer deposited on a ferromagnetic La2/3Sr1/3MnO3 film grown epitaxially on pseudocubic (001)-oriented SrTiO3, (LaAlO3)0.3

• using the pulsed-laser deposition technique. We analyzed the films structurally through X-ray reciprocal space maps and high-angle annular dark field microscopy, and magnetically via thermal demagnetization curves and in-plane magnetization versus applied magnetic field loops at room temperature. Our

• results indicate that the BaTiO3 layer induces an additional strain in the La2/3Sr1/3MnO3 layers close to their common interface. The presence of BaTiO3 on the surface of tensile-strained La2/3Sr1/3MnO3 films transforms the in-plane biaxial magnetic anisotropy present in the single layer into an in-plane

Examination of the relationship between viscoelastic properties and the invasion of ovarian cancer cells by atomic force microscopy

• Mengdan Chen,
• Jinshu Zeng,
• Weiwei Ruan,
• Zhenghong Zhang,
• Yuhua Wang,
• Shusen Xie,
• Zhengchao Wang and
• Hongqin Yang

Beilstein J. Nanotechnol. 2020, 11, 568–582, doi:10.3762/bjnano.11.45

• cells could be detected biomechanically. At present, a variety of research technologies, such as optical tweezers, micropipette aspiration, magnetic twisting cytometry and atomic force microscopy (AFM), have been developed to characterize the mechanical properties of biological samples [7][8][9][10

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

• TEOS was added to a solution containing ethanol, ammonia (33%) and ultrapure water under magnetic stirring and at room temperature for 30–40 min. The ratio of the reagents was modified in order to control the NPs size (Table 2). The NP suspension was centrifuged at 11,000 rcf for 15 min and the

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

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

• allowed for plasmonic and magnetic resonance, and luminescence in a single composite system for plasmonic photothermal therapy (PPTT). The bioimaging capability of the plasmonic magneto-luminescent multifunctional nanocarrier (PML-MF) systems were studied in vitro using three types of cancer cells, namely

• endocytosis. The superparamagnetic nature of the PML-MF allowed for the magnetic targeting of the nanocarriers. Further, the ability of BSA to encapsulate drug molecules was explored to load doxorubicin (DPML-MF) in the nanocarriers. The release kinetics of doxorubicin studied at pH 7.4 and 4.4 were found to

• property of the nanocarriers also allowed for magnetic targeting (Figure 5C). In another recent study, Pan et al. using glutathione-capped AuNCs showed that the aggregation-induced emission could be sensitive to the viscosity of the medium and that can potentially be used for intracellular viscosity

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

• efforts were also made to release the payload under the exposure of external (modern) triggers such as laser light, ultrasound, magnetic field, enzymatic deformation and mechanical deformation. In the latter cases, the capsules were irreversibly ruptured and released the loaded molecules either in a burst

• NPs, magnetic NPs, click moieties, smart polymers and biomolecules such as proteins, peptides, nucleic acids, and enzymes. Nanoparticle incorporation When NPs are embedded into the multilayer shell, the translocation, guiding and release of encapsulated cargo from the capsule is enabled by selectively

• changing the integrity or permeability. Magnetic NPs have shown greater cytotoxicity in comparison with microcapsules containing an equivalent amount of magnetite [79]. The first and foremost way of incorporating NPs into the shell is either by the adsorption of NPs over the sacrificial template or using

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• from the SiO2 layer do not exceed 2%. A light source of 460 nm wavelength has been used, propagating along the y axis direction. Two independent simulations were performed, one with a transverse-electric (TE) polarized beam and the second one with a transverse-magnetic (TM) polarized beam. These

• perpendicularly polarized beams yield, by averaging, the result for the unpolarized beam, according to the formula: where ETE and ETM are electric and magnetic fields obtained from simulations with TE and TM beam polarizations, respectively. For calculations of the electric field distribution, the shape of the

Preparation and in vivo evaluation of glyco-gold nanoparticles carrying synthetic mycobacterial hexaarabinofuranoside

• Gennady L. Burygin,
• Polina I. Abronina,
• Nikita M. Podvalnyy,
• Sergey A. Staroverov,
• Leonid O. Kononov and
• Lev A. Dykman

Beilstein J. Nanotechnol. 2020, 11, 480–493, doi:10.3762/bjnano.11.39

• nanoparticles (GNPs, average diameter d = 15 nm, Figure 2) were prepared by the citrate method of Frens [67][94]. For reduction, 0.01% aqueous tetrachloroauric acid (242.5 mL, HAuCl4; Sigma-Aldrich) in an Erlenmeyer flask was brought to reflux with stirring on a magnetic stirrer. Then 1% aqueous sodium citrate

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

• Berkin Uluutku and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 453–465, doi:10.3762/bjnano.11.37

• impart a sufficiently large oscillation amplitude for a proper application of intermittent-contact AFM methods. Addressing this challenge may require either developments in excitation systems or probe developments. Other excitation approaches, such as magnetic excitation, may also be problematic due to