5597531 Resuspendable coated magnetic particles and stable magnetic particle suspensions

Magnetic particles have been evaluated for their biomedical applications as a drug delivery system to treat asthma and other lung diseases. In this study, ferromagnetic barium hexaferrite (BaFe12O19) and iron oxide (Fe3O4) particles were suspended in water or glycerol, as glycerol can be 1000 times more viscous than water. The particle concentration was 2.50 mg/mL for BaFe12O19 particle clusters and 1.00 mg/mL for Fe3O4 particle clusters. The magnetic particle cluster cross-sectional area ranged from 15 to 1000 μμm2, and the particle cluster diameter ranged from 5 to 45 μμm. The magnetic particle clusters were exposed to oscillating or rotating magnetic fields and imaged with an optical microscope. The oscillation frequency of the applied magnetic fields, which was created by homemade wire spools inserted into an optical microscope, ranged from 10 to 180 Hz. The magnetic field magnitudes varied from 0.25 to 9 mT. The minimum magnetic field required for particle cluster rotation or oscillation in glycerol was experimentally measured at different frequencies. The results are in qualitative agreement with a simplified model for single-domain magnetic particles, with an average deviation from the model of 1.7 ± 1.3. The observed difference may be accounted for by the fact that our simplified model does not include effects on particle cluster motion caused by randomly oriented domains in multi-domain magnetic particle clusters, irregular particle cluster size, or magnetic anisotropy, among other effects.

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Development of a bacterial DNA extraction modular chip using a magnetic particle and portable vibration motor

Analytical Methods ◽

10.1039/c9ay02690h ◽

2020 ◽

Vol 12 (9) ◽

pp. 1197-1202

Author(s):

Sun Young Lim ◽

Tae Jae Lee ◽

Seol Yi Shin ◽

Nam Ho Bae ◽

Seok Jae Lee ◽

...

Keyword(s):

Power System ◽

Electric Power ◽

Dna Extraction ◽

Magnetic Particles ◽

Magnetic Particle ◽

Electric Power System ◽

Bacterial Dna ◽

System P ◽

3D Printed ◽

Bacterial Dna Extraction

The bacterial DNA was simply purified by magnetic particles with a portable vibration motor. To effectively extract DNA in the field, the 3D-printed device was employed with low electric power system.

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Rheological study of magnetic particle suspensions

Materials Chemistry and Physics ◽

10.1016/s0254-0584(97)80168-x ◽

1997 ◽

Vol 49 (3) ◽

pp. 225-228 ◽

Cited By ~ 3

Author(s):

T.M. Kwon ◽

M.S. John ◽

H.J. Choi

Keyword(s):

Magnetic Particle ◽

Particle Suspensions ◽

Rheological Study

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Gold Magnetic Particle Based Immunoassay on a Disposable Microchips

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.1931 ◽

2011 ◽

Vol 236-238 ◽

pp. 1931-1934

Author(s):

Zi Ye Wang ◽

Kang Wang ◽

Xue Mei Ma

Keyword(s):

Magnetic Nanoparticles ◽

Reaction Time ◽

Laser Ablation ◽

Magnetic Particles ◽

Magnetic Particle ◽

Binding Assay ◽

Igg Binding

Microchips appear to offer important opportunities for modern research. Microchips based on gold magnetic nanoparticles make manipulation of biomolecules more conveniently, and has the advantage of deducing reaction time. In this study, we first achieved microchips design and fabrication through CO2 laser ablation for immunoassay, and then conjugated mouse IgG to gold magnetic nanoparticles serve as a target. Finally, HRP labeled goat anti mouse IgG binding assay and substrate reaction were performed with disposable microchips and other devices. The results indicated that the reactions carried on successfully and magnetic particles moved well in chips.

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Synthesis of transparent magnetic particle/organic hybrid film using iron–organics

Journal of Materials Research ◽

10.1557/jmr.2000.0304 ◽

2000 ◽

Vol 15 (10) ◽

pp. 2114-2120 ◽

Cited By ~ 18

Author(s):

Toshinobu Yogo ◽

Tomoyuki Nakamura ◽

Wataru Sakamoto ◽

Shin-ichi Hirano

Keyword(s):

Iron Oxide ◽

Magnetization Curve ◽

Magnetic Particles ◽

Magnetic Particle ◽

Hybrid Film ◽

Oxide Particle ◽

Iron Oxide Particle ◽

Organic Hybrid ◽

Hydrolysis Conditions

A transparent magnetic particle/organic film was synthesized from an iron–organic compound. Iron(III) 3-allylacetylacetonate (IAA) was polymerized followed by in situ hydrolysis yielding an iron oxide particle/oligomer hybrid. The sizes of magnetic particles were dependent upon the hydrolysis conditions of the IAA oligomers. A nanometer-sized ferrimagnetic iron oxide particle/oligomer hybrid showed a magnetization curve with no coercive force at 300 K and that with Hc of 200 Oe at 4.2 K, respectively. The magnetization versus H/T curves at 300 and 77 K were superimposed on each other and satisfied the Langevin equation. The transparent hybrid film showed a magnetization curve at room temperature. The absorption spectrum of the film was shifted to higher energy by 0.14 eV compared with that of bulk magnetite. The absorption edge of the film was blue-shifted.

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Reviewing Magnetic Particle Preparation: Exploring the Viability in Biosensing

Sensors ◽

10.3390/s20164596 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4596

Author(s):

Daniel Kappe ◽

Laila Bondzio ◽

Joris Swager ◽

Andreas Becker ◽

Björn Büker ◽

...

Keyword(s):

Magnetic Particles ◽

Magnetic Particle ◽

Size Range ◽

Particle System ◽

Microfluidic Channel ◽

Review Article ◽

Particle Systems ◽

Heusler Compound ◽

Particle Preparation ◽

New Applications

In this review article, we conceptually investigated the requirements of magnetic nanoparticles for their application in biosensing and related them to example systems of our thin-film portfolio. Analyzing intrinsic magnetic properties of different magnetic phases, the size range of the magnetic particles was determined, which is of potential interest for biosensor technology. Different e-beam lithography strategies are utilized to identify possible ways to realize small magnetic particles targeting this size range. Three different particle systems from 500 μm to 50 nm are produced for this purpose, aiming at tunable, vertically magnetized synthetic antiferromagnets, martensitic transformation in a single elliptical, disc-shaped Heusler Ni50Mn32.5Ga17.5 particle and nanocylinders of Co2MnSi-Heusler compound. Perspectively, new applications for these particle systems in combination with microfluidics are addressed. Using the concept of a magnetic on–off ratchet, the most suitable particle system of these three materials is validated with respect to magnetically-driven transport in a microfluidic channel. In addition, options are also discussed for improving the magnetic ratchet for larger particles.

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Experimental Investigation of Magnetic Particle Movement in Two-Phase Vertical Flow under an External Magnetic Field Using 2D LIF-PIV

Applied Sciences ◽

10.3390/app10113976 ◽

2020 ◽

Vol 10 (11) ◽

pp. 3976

Author(s):

Changje Lee ◽

Yong-Seok Choi

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Magnetic Particles ◽

Magnetic Particle ◽

Two Phase Flow ◽

Scattered Light ◽

Laser Sheet ◽

Phase Flow ◽

Particle Movement ◽

Two Phase

In this study, we experimentally investigated magnetic particle movement in two-phase flow under an external magnetic field. According to Faraday’s law, the alignment of a magnet is important for power generation. For high generation, it is important to understand how magnetic particles move in two-phase flow. The rotationality could be determined by observing a single particle; however, this is impossible due to the flow conditions. In this study, we estimated nonrotationality based on the vorticity. To eliminate scattered light and improve the signal-to-noise ratio, the laser-induced fluorescence particle image velocimetry technique was used. The solenoid nozzle has a hydraulic diameter of 3 mm. Its surface is covered with a coil with a diameter of 0.3 mm. The average diameter of a magnetic particle is 1.2 μm. The excitation and emission wavelengths are 532 and 612 nm, respectively. A thin laser sheet setup was configured. The laser sheet was illuminated on both sides to prevent shadows. The images were captured at 200 μm away from the wall and center of the nozzle. To estimate the decrease in vorticity, the theoretical and single-phase non-magnetic and magnetic particles are compared. The vorticity of magnetic particles is reduced by the external magnetic field.

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