Ferromagnetic resonance spectra of linear magnetosome chains

• Elizaveta M. Gubanova and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2024, 15, 157–167, doi:10.3762/bjnano.15.15

• genetic control, they turn out to be the perfect magnetic particles in terms of their crystal structure and shape. Therefore, it is reasonable to assume that the magnetic damping constant for magnetosomes takes relatively small values, κ ≤ 0.1. These values were mainly used in the calculations. However

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• sensor can approach F-sub, and then F-sub cutting and fluorescence signal amplification are carried out in the presence of analytes. Bakshi et al. proposed a cellular nanoreactor. It had two kinds of magnetic particles, each of which is functionalized by two components of the binary deoxyribozyme system

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

• conservative torques acting on the i-th nanoparticle. The forces acting on the nanoparticles of the system are the van der Waals forces, electrostatic repulsive forces, magnetic dipolar forces, steric repulsion forces and the random Brownian force [19][26][27][28][29]. The stabilisation of magnetic particles

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

• engineering [40] or to facilitate 3D printing of magnetized chitosan solutions into helical microswimmers for drug delivery [11]. In the future, the incorporation of magnetic particles into biocompatible fibers might pave the way for the development of new soft biological motors, which can mechanically steer

• [39]. Since the magnetic particles used in this work were approximately 100 nm in diameter, the wet-spun chitosan fibers obtained were clearly ferromagnetic rather than superparamagnetic [40]. This observation was confirmed by the magnetic hysteresis curves which showed a maximum remanent

• ] or loaded onto the fiber surface by a post-treatment [39]. To tailor our wet-spun magnetic chitosan fibers for possible applications in magnetic tissue engineering [44][46] it will be important to determine the effect that smaller magnetic particles have on the microfiber morphology, on the particle

Use of data processing for rapid detection of the prostate-specific antigen biomarker using immunomagnetic sandwich-type sensors

• Camila A. Proença,
• Tayane A. Freitas,
• Thaísa A. Baldo,
• Elsa M. Materón,
• Flávio M. Shimizu,
• Gabriella R. Ferreira,
• Frederico L. F. Soares,
• Ronaldo C. Faria and
• Osvaldo N. Oliveira Jr.

Beilstein J. Nanotechnol. 2019, 10, 2171–2181, doi:10.3762/bjnano.10.210

• ]. PSA and interleukin 6 (IL-6) were measured with a microfluidic electrochemical immunoassay system, in which commercial magnetic particles were conjugated with secondary antibodies and horseradish peroxidase (HRP) [26]. These immunomagnetic nanoparticle-based microfluidic sensors with screen-printed

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

• Małgorzata Świętek,
• Yi-Chin Lu,
• Rafał Konefał,
• Liliana P. Ferreira,
• M. Margarida Cruz,
• Yunn-Hwa Ma and
• Daniel Horák

Beilstein J. Nanotechnol. 2019, 10, 1073–1088, doi:10.3762/bjnano.10.108

• -Ultrasonics; Farmingdale, NY, USA; amplitude 10%) for 5 min. Heparin salt (4.05 mg) was dissolved in water (5 mL), added to the magnetic particles after sonication, and the mixture was vigorously vortexed for 2 h. The resulting γ-Fe2O3@Hep nanoparticles were washed with water two times (25 and 10 mL

• method chosen to attach phenolic compounds on the chitosan rather than by the phenolic compounds themselves. Moreover, the chitosans with low molecular weight were highly soluble in 2 wt % acetic acid; they could also be dissolved in water, which is important for surface modification of the magnetic

• particles. Antioxidant properties of chitosans modified with phenolic compounds The FC assay for colorimetric determination of total phenolic content in samples of natural origin is based on the electron transfer between a phenolic compound and a phosphomolybdic/phosphotungstic complex that emits at a

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances

• Kun Ren,
• Xiaobin Ren,
• Yumeng He and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 247–255, doi:10.3762/bjnano.10.23

• magnetic particles is 1.52% at 24.3 °C. The curve of nMF as function of H becomes saturated at H > 200 Oe. The response of the refractive index to H is nonlinear, but in the range of 40–100 Oe, the response shows a good linearity. Therefore field strengths of H = 40–100 Oe are considered in this paper. nMF

Cytotoxicity of doxorubicin-conjugated poly[N-(2-hydroxypropyl)methacrylamide]-modified γ-Fe₂O₃ nanoparticles towards human tumor cells

• Zdeněk Plichta,
• Yulia Kozak,
• Rostyslav Panchuk,
• Viktoria Sokolova,
• Matthias Epple,
• Lesya Kobylinska,
• Pavla Jendelová and
• Daniel Horák

Beilstein J. Nanotechnol. 2018, 9, 2533–2545, doi:10.3762/bjnano.9.236

• free doxorubicin. The newly developed doxorubicin-conjugated PHPMA-coated magnetic particles seem to be a promising magnetically targeted vehicle for anticancer drug delivery. Keywords: cytotoxicity; doxorubicin; magnetic; nanoparticles; poly[N-(2-hydroxypropyl)methacrylamide]; Introduction Severe

Enzymatically promoted release of organic molecules linked to magnetic nanoparticles

• Chiara Lambruschini,
• Silvia Villa,
• Luca Banfi,
• Fabio Canepa,
• Fabio Morana,
• Annalisa Relini,
• Paola Riani,
• Renata Riva and
• Fulvio Silvetti

Beilstein J. Nanotechnol. 2018, 9, 986–999, doi:10.3762/bjnano.9.92

• disperse ultrafine magnetic particles to a final concentration of 17 g/L. Synthesis of conjugated nanoparticles 9: 28.6 mg of NP@APTES were dispersed in dry DCM (2 mL) under N2 atmosphere. Et3N (19 μL, 135 μmol) and bis(trichloromethyl)carbonate (triphosgene) (5.4 mg, 18 μmol) were added at 0 °C. The

Magnetic field induced orientational transitions in liquid crystals doped with carbon nanotubes

• Danil A. Petrov,
• Pavel K. Skokov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2807–2817, doi:10.3762/bjnano.8.280

• quadrupole response to the magnetic field applied perpendicularly to the initial alignment of the magnetic subsystems. They exhibit a threshold Fréedericksz transition from the initial compensated phase (planar phase) to the non-uniform angular phase, like the CNT suspensions. For weak coupling of magnetic

• particles and LC matrix the following sequence of reentrant transitions takes place: initial uniform compensated phase (planar phase) – non-uniform phase (angular phase) – uniform saturation phase (homeotropic phase) – non-uniform phase (planar phase). For strong coupling of ferroparticles with the LC

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• mechanism of interaction between the LC and an external magnetic field, the addition of magnetic particles into the LC leads to the appearance of an additional dipole mechanism of the influence on the system. Some types of synthesized ferroliquid crystals have ferromagnetic properties and are highly

• strength Hc [13]. Because χa is small, the value of Hc in a CLC is relatively large. The inclusion of a small amount of magnetic particles into a CLC, as shown in [14][15][16][17], significantly changes the critical field for the unwinding of the ferrocholesteric helix. Moreover, the flow of a liquid

• orientational phases induced by a magnetic field and a shear flow in a ferronematic (i.e., in a nematic liquid crystal doped with magnetic particles) were studied both in an infinite sample [22], and in a restricted geometry [23]. It was revealed that shear flow can lead to the shift of the field thresholds or

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• saturation can be increased by about two orders of magnitude. This finding paves a way to application possibilities, such as low magnetic field sensors, or basic logical elements for information storage. Keywords: ac magnetic susceptibility; ferronematics; magnetic particles; Introduction The great

• ) [28][29]. This liquid-crystalline matrix was doped with spherical magnetic particles purchased from Ocean NanoTech. The mean diameter of the Fe3O4 magnetic particles was d = 20 nm. They were coated with oleic acid and dissolved in chloroform. This suspension was admixed to the liquid crystal, and the

Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• and f is the volume fraction of the magnetic particles. Considering the dynamic evolution of a liquid crystal system as presented in [34], we can evaluate the temporal evolution of the distortion angle using the model similar to the one used in [30]. In this model, the term used for an azo-dye

Methods for preparing polymer-decorated single exchange-biased magnetic nanoparticles for application in flexible polymer-based films

• Laurence Ourry,
• Delphine Toulemon,
• Souad Ammar and
• Fayna Mammeri

Beilstein J. Nanotechnol. 2017, 8, 408–417, doi:10.3762/bjnano.8.43

• decoration of NPs by oleic acid followed by ligand exchange with the desired bromopropionyl ester groups. We then built various assemblies of NPs directly on a substrate or suspended in PMMA. Conclusion: The alternative two-step strategy leads to better dispersed polymer-decorated magnetic particles, and the

• reported [15]. A chain density ranging between 0.1 and 1 chain nm−2 is commonly reported [13][26][31][32]. In the present case, a higher grafting density means better protection of the magnetic particles against oxidation and more stable magnetic properties over time [33]. Indeed, the aim here is not

• PS) functionalized magnetic particles with improved polymer chain grafting densities than those previously reported. However, it is still a serious challenge to separate all the particles and avoid a few aggregates. Hence, we replaced the centrifugation of the ENPs after the polyol synthesis by

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

• Maryam Daneshpour,
• Kobra Omidfar and
• Hossein Ghanbarian

Beilstein J. Nanotechnol. 2016, 7, 2023–2036, doi:10.3762/bjnano.7.193

• diameter of 13 nm (Figure 2A(c)). Presumably, the Fe3O4 cores were well covered by an intermediate coating layer of N-trimethylchitosan (TMC) with a thickness of about 2–3 nm during the synthesis process. The importance of this step is that using TMC for covering the magnetic particles does not increase

• –magnetic particles confirms not only the crystallinity of the nanostructures but also the presence of gold in the synthesized nanocomposite. The XRD result shows six significant reflections of the (220), (311), (422), (511), (440), and (533) plane spacings of the magnetite phase with spinel structure

An efficient recyclable magnetic material for the selective removal of organic pollutants

• Clément Monteil,
• Nathalie Bar,
• Agnès Bee and
• Didier Villemin

Beilstein J. Nanotechnol. 2016, 7, 1447–1453, doi:10.3762/bjnano.7.136

• with charged pollutants through amine or phosphonate groups. Washing steps and recyclability of the magnetic particles The data collected in Figure 4 reveal that the adsorption of MO with NP-PEIP05 is reduced to one third between pH 7 and 14. On the opposite, the MB adsorption falls from 1011 mg·g−1 to

• adjusted to pH 7 or 14 with nitric acid or sodium hydroxide. Moreover, only 20 mL are enough to wash up to 1 g of magnetic particles. Figure 5A shows that after a full adsorption of MO by NP-PEIP05 (orange bars), more than 68% of dye are released after the first wash and 83% after two successive washes. NP

• cycles (Figure 5B). A little loss of activity for MO and MB was observed but more than 90% of contaminants were removed after the seventh cycle. The loss in magnetic particles between cycles is negligible compared to the amount of pollutant extracted and in addition, no traces of iron were detected by

Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

• Julia Körner,
• Christopher F. Reiche,
• Thomas Gemming,
• Bernd Büchner,
• Gerald Gerlach and
• Thomas Mühl

Beilstein J. Nanotechnol. 2016, 7, 1033–1043, doi:10.3762/bjnano.7.96

• for applications in hypothermia treatment [2]. A technique to investigate such magnetic particles and samples is cantilever magnetometry. The measurement setup is based on a cantilever oscillating at or close to its resonance frequency, with the sample placed at the free end of the cantilever. When an

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• the last decades, different strategies have been developed toward this goal such as epitaxial heterocrystalline growth, co-encapsulation of preformed QDs and magnetic particles in silica beads, doping of QDs with transition metal ions, conjugation between magnetic chelates or magnetic nanocrystals

Radiation losses in the microwave K_u band in magneto-electric nanocomposites

• Talwinder Kaur,
• Sachin Kumar,
• Jyoti Sharma and
• A. K. Srivastava

Beilstein J. Nanotechnol. 2015, 6, 1700–1707, doi:10.3762/bjnano.6.173

• electromagnetic noise by using absorbing materials. Earlier, carbon black, metal flakes, iron balls and recently carbon nanotubes with magnetic particles were used as absorbent. However, there are some limitations such as a fixed absorption range, difficulties during synthesis, impedance matching problems [3

• the polymer contribute to high absorption over a wide range [5]. Hence, researchers turned their attention towards magnetic particles embedded in polymers [6][7][8][9][10][11][12] with a focus on composites of hexaferrite and conducting polymers [13][14][15][16][17][18]. M-type hexaferrite is an

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• that these polymers provide an adsorbent network on the surface of the Fe3O4 nanoparticles, it was decided to additionally assemble Au nanoparticles onto the polymer-coated magnetic particles, resulting in the development of novel nanocomposites. The final diameter of the resulting nanocomposite was

Thermal treatment of magnetite nanoparticles

• Beata Kalska-Szostko,
• Urszula Wykowska,
• Dariusz Satula and
• Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

• lack of temperature treatment stability and the evolution of different oxides show the complexity behind the science regarding the nanostructure study. The development of various magnetic particles originates from the same compound, which makes the nanoscience more unpredictable but, at the same time

Interaction of electromagnetic radiation in the 20–200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles

• Agylych Atdayev,
• Alexander L. Danilyuk and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2015, 6, 1056–1064, doi:10.3762/bjnano.6.106

• ][34]. The model of the interaction of EMR with CNT-based nanocomposite used in this work is based on a previously developed approach [8]. This approach relies on the modified Bruggeman effective medium theory, which takes into account the conductive magnetic particles randomly distributed in the

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• scanning microscope (Carl Zeiss Oberkochen, Germany). Results and Discussion Surface-modified γ-Fe2O3 particles In this report, non-coated γ-Fe2O3 nanoparticles served both as a control and as a core for post-synthesis coating with D-mannose and PDMAAm. TEM images of the synthesized magnetic particles did

Designing magnetic superlattices that are composed of single domain nanomagnets

• Derek M. Forrester,
• Feodor V. Kusmartsev and
• Endre Kovács

Beilstein J. Nanotechnol. 2014, 5, 956–963, doi:10.3762/bjnano.5.109

• when the coupling strength is altered. It is important to note that the interaction of magnetic disks in a stack may have a dipolar character. For example, if we consider two small elliptical magnetic particles in a vacuum, separated by large distances from each other so that each particle will have a

• combine analytical solutions, obtained through quasi-classical methods [15], with numerical solutions found through a full dynamical analysis. The result is a design ethic for creating superlattice structures composed of elliptically shaped and regularly patterned magnetic particles. The quasi-static

• in these systems. Indeed, we have found that chaos emerges within certain limits of the energy balances in the system, particularly for less elongated nanomagnets and those less damped. In our future publication we plan to address the issue of the chaos which may arise in the chains of magnetic

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• spectra of iron oxide before coating and after modification with D-mannose and the spectrum of D-mannose are displayed in Figure 2. Rather large iron oxide peaks were notable in the spectrum of the neat magnetic particles (Figure 2a). The characteristic bands of the C–H, C–O–H and C–O–C vibrations of D