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Publications (8 of 8) Show all publications
Riordan, E., Blomgren, J., Jonasson, C., Ahrentorp, F., Johansson, C., Margineda, D., . . . Giblin, S. R. (2019). Design and implementation of a low temperature, inductance based high frequency alternating current susceptometer.. Paper presented at 2019/08/08. Review of Scientific Instruments, 90(7)
Open this publication in new window or tab >>Design and implementation of a low temperature, inductance based high frequency alternating current susceptometer.
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2019 (English)In: Review of Scientific Instruments, Vol. 90, no 7Article in journal (Refereed) Published
Abstract [en]

We report on the implementation of an induction based, low temperature, high frequency ac susceptometer capable of measuring at frequencies up to 3.5 MHz and at temperatures between 2 K and 300 K. Careful balancing of the detection coils and calibration allow a sample magnetic moment resolution of 5 × 10−10 Am2 at 1 MHz. We discuss the design and characterization of the susceptometer and explain the calibration process. We also include some example measurements on the spin ice material CdEr2S4 and iron oxide based nanoparticles to illustrate functionality.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39702 (URN)10.1063/1.5074154 (DOI)
Conference
2019/08/08
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-08Bibliographically approved
Sriviriyakul, T., Bogren, S., Schaller, V., Jonasson, C., Blomgren, J., Ahrentorp, F., . . . Johansson, C. (2019). Nanorheological studies of xanthan/water solutions using magnetic nanoparticles. Journal of Magnetism and Magnetic Materials, 473, 268-271
Open this publication in new window or tab >>Nanorheological studies of xanthan/water solutions using magnetic nanoparticles
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2019 (English)In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 473, p. 268-271Article in journal (Refereed) Published
Abstract [en]

We show results of nanorheological studies of different concentrations of xanthan (non-Newtonian fluid) in water using magnetic nanoparticles (MNPs) together with the AC susceptibility (ACS) vs frequency method. For comparison we also show the ACS response for different concentrations of glycerol in water (Newtonian fluid). The ACS response is measured, and the data is modelled using dynamic magnetic models and different viscoelastic models. We study the ACS response (in-phase and out-of-phase ACS components) at different concentrations of xanthan in water (up to 1 wt% xanthan) and with a constant concentration of MNPs. We use MNP systems that show Brownian relaxation (sensitive to changes in the environmental properties around the MNPs). ACS measurements are performed using the DynoMag system. The Brownian relaxation of the MNP system peak is shifting down in frequency and the ACS response is broadening and decreases due to changes in the viscoelastic properties around the MNPs in the xanthan solution. The viscosity and the storage moduli are determined at each excitation frequency and compared with traditional macroscopic small amplitude oscillatory shear rheological measurements. The results from the traditional rheological and nanorheological measurements correlate well at higher xanthan concentration.

Place, publisher, year, edition, pages
Elsevier B.V., 2019
Keywords
AC susceptibility, Brownian relaxation, Glycerol, Magnetic multi-core nanoparticles, Nanorheological measurements, Xanthan, Brownian movement, Digital storage, Magnetic susceptibility, Nanoparticles, Non Newtonian flow, Non Newtonian liquids, Rheology, Viscoelasticity, Ac susceptibility (ACS), Brownian relaxations, Magnetic nano-particles, Magnetic nanoparti cles (MNPs), Multi core, Viscoelastic properties, Nanomagnetics
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-35560 (URN)10.1016/j.jmmm.2018.09.103 (DOI)2-s2.0-85055085870 (Scopus ID)
Note

; Funding details: Svenska Forskningsrådet Formas; Funding details: 2016-00253, Svenska Forskningsrådet Formas; Funding text: The authors acknowledge Josefine Mosser for assistance with experimental work. This project receives funding from The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning ( FORMAS ) under grant number 2016-00253 .

Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2019-06-27Bibliographically approved
Blomgren, J., Ahrentorp, F., Ilver, D., Jonasson, C., Sepehri, S., Kalaboukhov, A., . . . Johansson, C. (2018). Development of a sensitive induction-based magnetic nanoparticle biodetection method. Nanomaterials, 8(11), Article ID 887.
Open this publication in new window or tab >>Development of a sensitive induction-based magnetic nanoparticle biodetection method
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2018 (English)In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 11, article id 887Article in journal (Refereed) Published
Abstract [en]

We developed a novel biodetection method for influenza virus based on AC magnetic susceptibility measurement techniques (the DynoMag induction technique) together with functionalized multi-core magnetic nanoparticles. The sample consisting of an incubated mixture of magnetic nanoparticles and rolling circle amplified DNA coils is injected into a tube by a peristaltic pump. The sample is moved as a plug to the two well-balanced detection coils and the dynamic magnetic moment in each position is read over a range of excitation frequencies. The time for making a complete frequency sweep over the relaxation peak is about 5 minutes (10 Hz–10 kHz with 20 data points). The obtained standard deviation of the magnetic signal at the relaxation frequency (around 100 Hz) is equal to about 10−5 (volume susceptibility SI units), which is in the same range obtained with the DynoMag system. The limit of detection with this method is found to be in the range of 1 pM. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords
AC susceptibility, Brownian relaxation, Magnetic biosensing, Magnetic nanoparticles, Multi-core particles
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36359 (URN)10.3390/nano8110887 (DOI)2-s2.0-85056217345 (Scopus ID)
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2019-06-27Bibliographically approved
Gao, S., Zaharko, O., Tsurkan, V., Prodan, L., Riordan, E., Lago, J., . . . Fennell, T. (2018). Dipolar Spin Ice States with a Fast Monopole Hopping Rate in CdEr2X4 (X = Se, S). Physical Review Letters, 120(13), Article ID 130201.
Open this publication in new window or tab >>Dipolar Spin Ice States with a Fast Monopole Hopping Rate in CdEr2X4 (X = Se, S)
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2018 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 120, no 13, article id 130201Article in journal (Refereed) Published
Abstract [en]

Excitations in a spin ice behave as magnetic monopoles, and their population and mobility control the dynamics of a spin ice at low temperature. CdEr2Se4 is reported to have the Pauling entropy characteristic of a spin ice, but its dynamics are three orders of magnitude faster than the canonical spin ice Dy2Ti2O7. In this Letter we use diffuse neutron scattering to show that both CdEr2Se4 and CdEr2S4 support a dipolar spin ice state-the host phase for a Coulomb gas of emergent magnetic monopoles. These Coulomb gases have similar parameters to those in Dy2Ti2O7, i.e., dilute and uncorrelated, and so cannot provide three orders faster dynamics through a larger monopole population alone. We investigate the monopole dynamics using ac susceptometry and neutron spin echo spectroscopy, and verify the crystal electric field Hamiltonian of the Er3+ ions using inelastic neutron scattering. A quantitative calculation of the monopole hopping rate using our Coulomb gas and crystal electric field parameters shows that the fast dynamics in CdEr2X4 (X = Se, S) are primarily due to much faster monopole hopping. Our work suggests that CdEr2X4 offer the possibility to study alternative spin ice ground states and dynamics, with equilibration possible at much lower temperatures than the rare earth pyrochlore examples.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33635 (URN)10.1103/PhysRevLett.120.137201 (DOI)2-s2.0-85044749863 (Scopus ID)
Note

Foundation under Grants No. 20021-140862, No. 20020- 162626, and the SCOPES project No. IZ73Z0-152734/1.

Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2019-06-27Bibliographically approved
Ahrentorp, F., Blomgren, J., Jonasson, C., Sarwe, A., Sepehri, S., Eriksson, E., . . . Johansson, C. (2017). Sensitive magnetic biodetection using magnetic multi-core nanoparticles and RCA coils. Paper presented at 11th International Conference on the Scientific and Clinical Applications of Magnetic Carrier. Journal of Magnetism and Magnetic Materials, 427, 14-18
Open this publication in new window or tab >>Sensitive magnetic biodetection using magnetic multi-core nanoparticles and RCA coils
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2017 (English)In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 427, p. 14-18Article in journal (Refereed) Published
Abstract [en]

We use functionalized iron oxide magnetic multi-core particles of 100 nm in size (hydrodynamic particle diameter) and AC susceptometry (ACS) methods to measure the binding reactions between the magnetic nanoparticles (MNPs) and bio-analyte products produced from DNA segments using the rolling circle amplification (RCA) method. We use sensitive induction detection techniques in order to measure the ACS response. The DNA is amplified via RCA to generate RCA coils with a specific size that is dependent on the amplification time. After about 75 min of amplification we obtain an average RCA coil diameter of about 1 µm. We determine a theoretical limit of detection (LOD) in the range of 11 attomole (corresponding to an analyte concentration of 55 fM for a sample volume of 200 µL) from the ACS dynamic response after the MNPs have bound to the RCA coils and the measured ACS readout noise. We also discuss further possible improvements of the LOD.

Keywords
AC susceptometry, Biodetection, Differential induction coil, Magnetic multi-core particles, Magnetic nanoparticles, RCA coil, Magnetism, Nanoparticles, Differential induction, Magnetic nano-particles, Multi core, Nanomagnetics
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-29330 (URN)10.1016/j.jmmm.2016.10.041 (DOI)2-s2.0-85006097391 (Scopus ID)
Conference
11th International Conference on the Scientific and Clinical Applications of Magnetic Carrier
Available from: 2017-05-08 Created: 2017-05-08 Last updated: 2019-06-27Bibliographically approved
Sepehri, S., Eriksson, E., Kalaboukhov, A., Zardán Gómez de la Torre, T., Kustanovich, K., Jesorka, A., . . . Winkler, D. (2017). Volume-amplified magnetic bioassay integrated with microfluidic sample handling and high-Tc SQUID magnetic readout. APL Bioengineering, 2(1), Article ID 016102.
Open this publication in new window or tab >>Volume-amplified magnetic bioassay integrated with microfluidic sample handling and high-Tc SQUID magnetic readout
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2017 (English)In: APL Bioengineering, Vol. 2, no 1, article id 016102Article in journal (Refereed) Published
Abstract [en]

A bioassay based on a high-Tc superconducting quantum interference device (SQUID) reading out functionalized magnetic nanoparticles (fMNPs) in a prototype microfluidic platform is presented. The target molecule recognition is based on volume amplification using padlock-probe-ligation followed by rolling circle amplification (RCA). The MNPs are functionalized with single-stranded oligonucleotides, which give a specific binding of the MNPs to the large RCA coil product, resulting in a large change in the amplitude of the imaginary part of the ac magnetic susceptibility. The RCA products from amplification of synthetic Vibrio cholera target DNA were investigated using our SQUID ac susceptibility system in microfluidic channel with an equivalent sample volume of 3 μl. From extrapolation of the linear dependence of the SQUID signal versus concentration of the RCA coils, it is found that the projected limit of detection for our system is about 1.0 × 105 RCA coils (0.2 × 10−18 mol), which is equivalent to 66 fM in the 3 μl sample volume. This ultra-high magnetic sensitivity and integration with microfluidic sample handling are critical steps towards magnetic bioassays for rapid detection of DNA and RNA targets at the point of care.

Place, publisher, year, edition, pages
American Institute of Physics, 2017
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36362 (URN)10.1063/1.4999713 (DOI)
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2019-06-27Bibliographically approved
Ahrentorp, F., Astalan, A., Blomgren, J., Jonasson, C., Wetterskog, E., Svedlindh, P., . . . Johansson, C. (2015). Effective particle magnetic moment of multi-core particles (ed.). Journal of Magnetism and Magnetic Materials, 380, 221-226
Open this publication in new window or tab >>Effective particle magnetic moment of multi-core particles
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2015 (English)In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 380, p. 221-226Article in journal (Refereed) Published
Abstract [en]

In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy(TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

Keywords
Magnetic nanoparticles, Magnetic relaxation, Multi-core particles, Single-core particles
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-31914 (URN)10.1016/j.jmmm.2014.09.070 (DOI)
Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2019-07-08Bibliographically approved
Sjöberg, A., Blomgren, J., Erlandsson, M. & Johansson, C. (2007). Trådlösa fuktsensorer inom byggindustrin: en fältstudie av två trådlösa system för fukt- och temperaturmätnig.
Open this publication in new window or tab >>Trådlösa fuktsensorer inom byggindustrin: en fältstudie av två trådlösa system för fukt- och temperaturmätnig
2007 (Swedish)Report (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37735 (URN)
Available from: 2019-02-07 Created: 2019-02-07 Last updated: 2019-06-20Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6148-3574

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