scholarly journals Magnetic Particles: Their Applications from Sample Preparations to Biosensing Platforms

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 302 ◽  
Author(s):  
Seong-Eun Kim ◽  
My Van Tieu ◽  
Sei Young Hwang ◽  
Min-Ho Lee
Keyword(s):  
Iron Oxide ◽  
Magnetic Materials ◽  
Magnetic Particles ◽  
Ease Of Use ◽  
Iron Oxide Particles ◽  
Scientific Publications ◽  
Magnetic Iron Oxide ◽  
Automation Systems ◽  
Target Molecules ◽  
Oxide Particles

The growing interest in magnetic materials as a universal tool has been shown by an increasing number of scientific publications regarding magnetic materials and its various applications. Substantial progress has been recently made on the synthesis of magnetic iron oxide particles in terms of size, chemical composition, and surface chemistry. In addition, surface layers of polymers, silica, biomolecules, etc., on magnetic particles, can be modified to obtain affinity to target molecules. The developed magnetic iron oxide particles have been significantly utilized for diagnostic applications, such as sample preparations and biosensing platforms, leading to the selectivity and sensitivity against target molecules and the ease of use in the sensing systems. For the process of sample preparations, the magnetic particles do assist in target isolation from biological environments, having non-specific molecules and undesired molecules. Moreover, the magnetic particles can be easily applied for various methods of biosensing devices, such as optical, electrochemical, and magnetic phenomena-based methods, and also any methods combined with microfluidic systems. Here we review the utilization of magnetic materials in the isolation/preconcentration of various molecules and cells, and their use in various techniques for diagnostic biosensors that may greatly contribute to future innovation in point-of-care and high-throughput automation systems.

The Behavior of Surface Hydroxyl Group of Magnetic Iron Oxide Particles

Ferrites ◽  
1982 ◽  
pp. 545-547
Author(s):  
Hiroshi Sugihara ◽  
Yasuta Taketomi ◽  
Tatsuo Uehori ◽  
Yasuo Imaoka
Keyword(s):  
Iron Oxide ◽  
Hydroxyl Group ◽  
Iron Oxide Particles ◽  
Magnetic Iron Oxide ◽  
Surface Hydroxyl ◽  
Oxide Particles

Nanometer-Scale Iron Oxide Magnetic Particles: Synthesis and Magnetic Properties

1990 ◽  
Vol 206 ◽  
Author(s):  
John K. Vassiliou ◽  
Vivek Mehrotra ◽  
Michael W. Russell ◽  
Emmanuel P. Giannelis
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Oxide ◽  
Magnetic Particles ◽  
Average Diameter ◽  
Nanometer Scale ◽  
Iron Oxide Particles ◽  
Porous Network ◽  
Synthesis Conditions ◽  
Oxide Particles ◽  
The Magnetic Field

ABSTRACTNanometer-scale iron oxide magnetic particles have been formed in the porous network of a cross-linked polymer matrix by ion exchange and subsequent hydrolysis. The oxide particles are uniform, well-dispersed and spherical with a diameter ranging between 30 and 1200 Å depending on the synthesis conditions. The DC magnetic susceptibility, measured between 4 and 300 K, continuously increases with decreasing temperature and tends to saturate at low temperatures. Composites containing iron oxide particles with an average diameter of 80 Å exhibit superparamagnetism while those on the order of 1000 Å undergo an antiferromagnetic-type transition at 33 K. The magnetic susceptibility is critically dependent upon the particle size and the strength of the magnetic field.

Octylamine as a novel fuel for the preparation of magnetic iron oxide particles by an aqueous auto–ignition method

2019 ◽  
Vol 805 ◽  
pp. 545-550 ◽  
Author(s):  
Basam A.E. Ben-Arfa ◽  
Farzin Mohseni ◽  
Isabel M. Miranda Salvado ◽  
JoséM.F. Ferreira ◽  
João S. Amaral ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Particles ◽  
Magnetic Iron Oxide ◽  
Auto Ignition ◽  
Oxide Particles

Manipulation of Non-Magnetic Materials in Ferrofluid Containing Media

2005 ◽  
Vol 877 ◽  
Author(s):  
Derek Halverson ◽  
Ben Yellen ◽  
Gary Friedman
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
External Magnetic Field ◽  
Magnetic Materials ◽  
Time Varying ◽  
Magnetic Islands ◽  
Iron Oxide Particles ◽  
Novel Method ◽  
Oxide Particles

AbstractA novel method is proposed whereby non-magnetic objects can be moved along a surface at the microscale and nanoscale. It uses a negative magnetophoretic force, explained in the caption for figure one, on the non-magnetic objects which results from stabilized 10nm diameter iron oxide particles (ferrofluid) being attracted to regions of field maxima around magnetic islands on a surface, which pushes the non-magnetic objects to regions of field minima. By varying an external magnetic field we can control where these minima are and thus control how objects will position themselves with static fields and by using rotating time varying fields we can control how they move across the surface. This method does not require the objects to be initially in contact with the surface, as they will be pulled down to the surface from solution. While this paper deals with beads, any arbitrarily shaped object should be manipuable using this method. Additionally, while we address non-magnetic objects in this work similar methods could easily manipulate objects that are magnetic.

Encapsulation of ferromagnetic iron oxide particles by polyester resin

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
H. Baharvand
Keyword(s):  
Iron Oxide ◽  
Magnetic Particles ◽  
Polyester Resin ◽  
Thermo Gravimetric Analysis ◽  
Oxide Content ◽  
Gravimetric Analysis ◽  
Distribution Analysis ◽  
Polymer Phase ◽  
Iron Oxide Particles ◽  
Oxide Particles

AbstractMagnetic iron oxide (maghemite, Fe3O4) particles were encapsulated with polyester resin. The resulting magnetic powders were characterized by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fritsch particle sizer, scanning electron microscopy (SEM), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM) measurements. FTIR and XRD confirmed the presence of iron oxide in polymer phase. The TGA and DSC measurements indicated the magnetic polymer particles have more than 50% iron oxide content and high thermal stability. SEM revealed that all maghemite particles were embedded in the polymer phase. The size distribution analysis of prepared magnetic particles has shown that the mean diameter of the bare iron oxide particles slightly increased with encapsulation. According to our magnetometry data, shape of the loops evidences the ferromagnetic character of the material and no evidence of superparamagnetism was seen.

Magnetic Iron Oxide Particles Coated with Carboxydextran for Parenteral Administration and Liver Contrasting

1997 ◽  
Vol 38 (4) ◽  
pp. 584-597 ◽  
Author(s):  
R. Lawaczeck ◽  
H. Bauer ◽  
T. Frenzel ◽  
M. Hasegawa ◽  
Y. Ito ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Half Life ◽  
Liver Tumors ◽  
Spin Echo ◽  
Tumor Model ◽  
Hydrodynamic Diameter ◽  
Iron Oxide Particles ◽  
Magnetic Iron Oxide ◽  
Rat Tumor Model ◽  
Oxide Particles

Rationale and objectives: To evaluate the physical and pharmacological profiles of SH U555A, a suspension of magnetic iron oxide particles that is designed to enhance the visualization of liver tumors and metastases. Material and Methods: Chemical and physical methods were used to characterize the size and structure of these magnetic iron oxide particles in aqueous solution. The biodistribution and pharmacokinetics of the particles were studied in mice, rats and dogs. The imaging efficacy of the particles was demonstrated by MR imaging in rat liver tumors Results: The SH U555A particles consist of low-molecular-weight carboxydextran-coated iron oxides predominantly of the γ-Fe2O3 form with a hydrodynamic diameter ranging from 57-59 nm and strong T2 relaxivity of 164 liters * mmol−1 * S−1 (water, 0.47 T). In rats the particles exhibited a dose-dependent half-life of between 2 and 3 days in the liver at a dose of 20 μmol Fe/kg and a shorter half-life at lower doses. No major side effects were found. In a rat tumor model the tumor-to-liver contrast was markedly improved after i.v. administration of SH U555A. At a dose of 14 μmol Fe/kg the half-maximal contrast-effect was obtained even in nonoptimized T1-weighted spin-echo images. Conclusion: SH U555A is a superparamagnetic MR contrast agent for i.v. administration and has substantial potential for the demarcation of liver tumors.

scholarly journals Magnetic microparticle concentration and collection using a mechatronic magnetic ratcheting system

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246124
Author(s):  
Oladunni B. Adeyiga ◽  
Coleman Murray ◽  
Hector E. Muñoz ◽  
Alberto Escobar ◽  
Dino Di Carlo
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Concentration Factor ◽  
Magnetic Particles ◽  
Superparamagnetic Iron Oxide ◽  
Iron Oxide Particles ◽  
Superparamagnetic Iron Oxide Particles ◽  
Oxide Particles

Magnetic ratcheting cytometry is a promising approach to separate magnetically-labeled cells and magnetic particles based on the quantity of magnetic material. We have previously reported on the ability of this technique to separate magnetically-labeled cells. Here, with a new chip design, containing high aspect ratio permalloy micropillar arrays, we demonstrate the ability of this technique to rapidly concentrate and collect superparamagnetic iron oxide particles. The platform consists of a mechatronic wheel used to generate and control a cycling external magnetic field that impinges on a “ratcheting chip.” The ratcheting chip is created by electroplating a 2D array of high aspect ratio permalloy micropillars onto a glass slide, which is embedded in a thin polymer layer to create a planar surface above the micropillars. By varying magnetic field frequency and direction through wheel rotation rate and angle, we direct particle movement on chip. We explore the operating conditions for this system, identifying the effects of varying ratcheting frequency, along with time, on the dynamics and resulting concentration of these magnetic particles. We also demonstrate the ability of the system to rapidly direct the movement of superparamagnetic iron oxide particles of varying sizes. Using this technique, 2.8 μm, 500 nm, and 100 nm diameter superparamagnetic iron oxide particles, suspended within an aqueous fluid, were concentrated. We further define the ability of the system to concentrate 2.8 μm superparamagnetic iron oxide particles, present in a liquid suspension, into a small chip surface area footprint, achieving a 100-fold surface area concentration, and achieving a concentration factor greater than 200%. The achieved concentration factor of greater than 200% could be greatly increased by reducing the amount of liquid extracted at the chip outlet, which would increase the ability of achieving highly sensitive downstream analytical techniques. Magnetic ratcheting-based enrichment may be useful in isolating and concentrating subsets of magnetically-labeled cells for diagnostic automation.

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