| 1. |
- Bogren, Sara, et al.
(författare)
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Classification of Magnetic Nanoparticle Systems—Synthesis, Standardization and Analysis Methods in the NanoMag Project
- 2015
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 16:9, s. 20308-20325
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Tidskriftsartikel (refereegranskat)abstract
- This study presents classification of different magnetic single- and multi-core particle systems using their measured dynamic magnetic properties together with their nanocrystal and particle sizes. The dynamic magnetic properties are measured with AC (dynamical) susceptometry and magnetorelaxometry and the size parameters are determined from electron microscopy and dynamic light scattering. Using these methods, we also show that the nanocrystal size and particle morphology determines the dynamic magnetic properties for both single- and multi-core particles. The presented results are obtained from the four year EU NMP FP7 project, NanoMag, which is focused on standardization of analysis methods for magnetic nanoparticles.
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| 2. |
- Eberbeck, Dietmar, et al.
(författare)
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AC susceptometry and magnetorelaxometry for magnetic nanoparticle based biomolecule detection
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Functionalized magnetic nanoparticles are increasingly used as probes in biomolecule detection. We compared two different techniques, which provide information on the state of the magnetic particle system. The dynamics of an ensemble of magnetic nanoparticles was probed measuring the response its magnetisation both on an alternating magnetic field by AC-susceptometry and on a jump of external magnetic field by magnetorelaxometry. In order to compare both techniques, we studied the binding of streptavidin functionalized nanoparticles (fluidMAG/BC-SAV) to biotin-agarose beads and to biotinylated prostate specific antigens (PSA-10). By both techniques we observed specific changes in shape and amplitude of the characteristic signals due the binding of the particles. Therewith the signals of bound and unbound probes can be discriminated and a homogeneous assay without time-comsuming washing steps is realized. The AC susceptometry method provides a robust and sensitive measurement technology. Magnetorelaxometry, utilizing superconducting quantum interference devices (SQUIDs) as magnetic field sensors, owns a much shorter measurement time and has the potential of an even higher sensitivity, at the expense of a considerably increased technological effort.
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| 3. |
- Ludwig, Frank, et al.
(författare)
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Magnetic, Structural, and Particle Size Analysis of Single- and Multi-Core Magnetic Nanoparticles
- 2014
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Ingår i: IEEE Transactions on Magnetics. - 0018-9464 .- 1941-0069. ; 50:11
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Tidskriftsartikel (refereegranskat)abstract
- We have measured and analyzed three different commercial magnetic nanoparticle systems, both multi-core and single-core in nature, with the particle (core) size ranging from 20 to 100 nm. Complementary analysis methods and same characterization techniques were carried out in different labs and the results are compared with each other. The presented results primarily focus on determining the particle size-both the hydrodynamic size and the individual magnetic core size-as well as magnetic and structural properties. The used analysis methods include transmission electron microscopy, static and dynamic magnetization measurements, and Mossbauer spectroscopy. We show that particle (hydrodynamic and core) size parameters can be determined from different analysis techniques and the individual analysis results agree reasonably well. However, in order to compare size parameters precisely determined from different methods and models, it is crucial to establish standardized analysis methods and models to extract reliable parameters from the data.
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| 4. |
- Ludwig, Frank, et al.
(författare)
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Size analysis of single-core magnetic nanoparticles
- 2017
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Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 427, s. 19-24
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Tidskriftsartikel (refereegranskat)abstract
- Single-core iron-oxide nanoparticles with nominal core diameters of 14 nm and 19 nm were analyzed with a variety of non-magnetic and magnetic analysis techniques, including transmission electron microscopy (TEM), dynamic light scattering (DLS), static magnetization vs. magnetic field (M-H) measurements, ac susceptibility (ACS) and magnetorelaxometry (MRX). From the experimental data, distributions of core and hydrodynamic sizes are derived. Except for TEM where a number-weighted distribution is directly obtained, models have to be applied in order to determine size distributions from the measurand. It was found that the mean core diameters determined from TEM, M-H, ACS and MRX measurements agree well although they are based on different models (Langevin function, Brownian and Néel relaxation times). Especially for the sample with large cores, particle interaction effects come into play, causing agglomerates which were detected in DLS, ACS and MRX measurements. We observed that the number and size of agglomerates can be minimized by sufficiently strong diluting the suspension.
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| 5. |
- Posth, Oliver, et al.
(författare)
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Classification of analysis methods for characterization of magnetic nanoparticle properties
- 2015
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Ingår i: 21st IMEKO World Congress 2015. - 9781510812925 ; , s. 1310-1315
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Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to provide a roadmap for the standardization of magnetic nanoparticle (MNP) characterization. We have assessed common MNP analysis techniques under various criteria in order to define the methods that can be used as either standard techniques for magnetic particle characterization or those that can be used to obtain a comprehensive picture of a MNP system. This classification is the first step on the way to develop standards for nanoparticle characterization.
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| 6. |
- Rubia-Rodríguez, Irene, et al.
(författare)
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Whither Magnetic Hyperthermia? : A Tentative Roadmap
- 2021
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- The scientific community has made great efforts in advancing magnetic hyperthermia for the last two decades after going through a sizeable research lapse from its establishment. All the progress made in various topics ranging from nanoparticle synthesis to biocompatibilization and in vivo testing have been seeking to push the forefront towards some new clinical trials. As many, they did not go at the expected pace. Today, fruitful international cooperation and the wisdom gain after a careful analysis of the lessons learned from seminal clinical trials allow us to have a future with better guarantees for a more definitive takeoff of this genuine nanotherapy against cancer. Deliberately giving prominence to a number of critical aspects, this opinion review offers a blend of state-of-the-art hints and glimpses into the future of the therapy, considering the expected evolution of science and technology behind magnetic hyperthermia.
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| 7. |
- Wells, James, et al.
(författare)
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Standardisation of magnetic nanoparticles in liquid suspension
- 2017
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Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 50:383003, s. 1-25
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Tidskriftsartikel (refereegranskat)abstract
- Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation,spanning a large number of industry sectors from imaging and actuation based applicationsin biomedicine and biotechnology, through large-scale environmental remediation uses suchas water purification, to engineering-based applications such as position-controlled lubricantsand soaps. Continuous advances in their manufacture have produced an ever-growing rangeof products, each with their own unique properties. At the same time, the characterisation ofmagnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpretthe measurement data. In many cases, the stringent requirements of the end-user technologiesdictate that magnetic nanoparticle products should be clearly defined, well characterised,consistent and safe; or to put it another way—standardised. The aims of this document areto outline the concepts and terminology necessary for discussion of magnetic nanoparticles,to examine the current state-of-the-art in characterisation methods necessary for the mostprominent applications of magnetic nanoparticle suspensions, to suggest a possible structurefor the future development of standardisation within the field, and to identify areas and topicswhich deserve to be the focus of future work items. We discuss potential roadmaps for thefuture standardisation of this developing industry, and the likely challenges to be encounteredalong the way.
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