Biomolecular reactions studied using changes in Brownian rotation dynamics of magnetic particles

Astalan, Andrea Prieto; Ahrentorp, Fredrik; Johansson, Christer; Larsson, Kerstin; Krozer, Anatol

doi:10.1016/j.bios.2003.09.005

Cited by 162 publications

(121 citation statements)

References 10 publications

Supporting

Mentioning

118

Contrasting

Unclassified

Order By: Relevance

“…alternating and rotating) has recently become a potent tool for detection of proteins and molecules bound to the NPs. [1][2][3][4][5][6] To conduct a successful homogeneous magnetic bioassay, particularly in a rotating magnetic field (RMF), the iron oxide NP aqueous suspensions relaxing via the Brownian mechanism (d core > 24 nm) are required.…”

Section: Introductionmentioning

confidence: 99%

Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays

et al. 2013

View full text Add to dashboard Cite

CitationHighly Uniformly sized and shaped iron oxide nanoparticles with a mean size of 25 nm were synthesized via decomposition of ironoleate. High resolution transmission electron microscopy and Mössbauer spectroscopy investigations revealed that the particles are spheres primarily composed of Fe 3 O 4 with a small fraction of FeO. From Mössbauer and static magnetization measurements, it was deduced that the particles are superparamagnetic at room temperature. The hydrophobic particles were successfully transferred into water via PEGylation using nitrodopamine as an anchoring group. IR spectroscopy and thermogravimetric analysis showed the success and efficiency of the phase transfer reaction. After the PEGylation, the particles retained monodisperse and their magnetic core remained intact as proven by photon cross-correlation spectrocopy, ac susceptibility, and transmission electron microscopy. The particle aqueous suspensions revealed an excellent water stability over a month of monitoring and also against temperature up to 40 • C. The particles exhibited a moderate cytotoxic effect on in vitro cultured bone marrow-derived macrophages and no release of inflammatory or anti-inflammatory cytokines. The PEGylated particles were functionalized with Herceptin antibodies via a conjugation chemistry, their response to a rotating magnetic field was studied using a fluxgate-based setup and was compared with the one recorded for hydrophobic and PEGylated particles. The particle phase lag rose after labeling with Herceptin, indicating the successful conjugation of Herceptin antibodies to the particles.

show abstract

Section: Introductionmentioning

confidence: 99%

Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Among them, the ac susceptibility-based magnetic biosensing [6][7][8] is one of the most promising applications because the method has a potential for realizing the simple wash-free detection of a trace amount of target substances such as antigens and cancer markers in body fluids. That is, the ac susceptibility-based magnetic biosensing is applicable to early detection of diseases.…”

Section: Introductionmentioning

confidence: 99%

“…N B 1 1 1 ( 6 ) As shown in Eq. (6), the effective relaxation is a combination of both relaxation mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Fe3O4 nanorods designed for liquid-phase magnetic biosensing

Yasuda

Kitamoto

2018

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Alternating current (ac) susceptibility-based magnetic biosensing techniques in liquids are promising biomedical applications of magnetic nanoparticles because the methods have a potential for realizing the simple washfree detection of diseases. Controlling magnetic relaxation of nanoparticles is crucial in the biosensing; Brownian relaxation based on the particle rotation in liquids should be dominant to improve the sensitivity. Therefore, we focus on magnetically anisotropic Fe3O4 nanorods because it is considered that the particle rotation dominates magnetic response of suspended Fe3O4 nanorods due to the shape magnetic anisotropy. In the present paper, the Fe3O4 nanorods are fabricated and the dynamic magnetic response of Fe3O4 nanorods is evaluated under the liquid phase and the solid phase.

show abstract

“…The hydrodynamic diameter of the magnetic beads can be determined by measuring the Brownian relaxation frequency. 8 For both surface-and volume-based sensing, the magnetic beads are traditionally detected by either superconducting quantum interference devices (SQUIDs), 9 inductive methods, 10 fluxgates, 11 magneto-optical methods, 12 or magnetoresistive sensors. 7,[13][14][15] All methods, except for magneto-optical detection, directly measure the magnetic field from the magnetic beads.…”

Section: Introductionmentioning

confidence: 99%

Planar Hall effect bridge geometries optimized for magnetic bead detection

Østerberg

Rizzi

Henriksen

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inNovel designs of planar Hall effect bridge sensors optimized for magnetic bead detection are presented and characterized. By constructing the sensor geometries appropriately, the sensors can be tailored to be sensitive to an external magnetic field, the magnetic field due to beads being magnetized by the sensor self-field or a combination thereof. The sensors can be made nominally insensitive to small external magnetic fields, while being maximally sensitive to magnetic beads, magnetized by the sensor self-field. Thus, the sensor designs can be tailored towards specific applications with minimal influence of external variables. Three different sensor designs are analyzed theoretically. To experimentally validate the theoretical signals, two sets of measurements are performed. First, the sensor signals are characterized as function of an externally applied magnetic field. Then, measurements of the dynamic magnetic response of suspensions of magnetic beads with a nominal diameter of 80 nm are performed. Furthermore, a method to amplify the signal by appropriate combinations of multiple sensor segments is demonstrated. V C 2014 AIP Publishing LLC.

show abstract

Biomolecular reactions studied using changes in Brownian rotation dynamics of magnetic particles

Cited by 162 publications

References 10 publications

Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays

Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays

Fabrication of Fe3O4 nanorods designed for liquid-phase magnetic biosensing

Planar Hall effect bridge geometries optimized for magnetic bead detection

Contact Info

Product

Resources

About