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Sepehri, S., Zardán Gómez De La Torre, T., Schneiderman, J. F., Blomgren, J., Jesorka, A., Johansson, C., . . . Kalaboukhov, A. (2020). Homogeneous Differential Magnetic Assay. ACS Sensors
Open this publication in new window or tab >>Homogeneous Differential Magnetic Assay
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2020 (English)In: ACS Sensors, ISSN 2379-3694Article in journal (Refereed) In press
Abstract [en]

Assays are widely used for detection of various targets, including pathogens, drugs, and toxins. Homogeneous assays are promising for the realization of point-of-care diagnostics as they do not require separation, immobilization, or washing steps. For low concentrations of target molecules, the speed and sensitivity of homogeneous assays have hitherto been limited by slow binding kinetics, time-consuming amplification steps, and the presence of a high background signal. Here, we present a homogeneous differential magnetic assay that utilizes a differential magnetic readout that eliminates previous limitations of homogeneous assays. The assay uses a gradiometer sensor configuration combined with precise microfluidic sample handling. This enables simultaneous differential measurement of a positive test sample containing a synthesized Vibrio cholerae target and a negative control sample, which reduces the background signal and increases the readout speed. Very low concentrations of targets down to femtomolar levels are thus detectable without any additional amplification of the number of targets. Our homogeneous differential magnetic assay method opens new possibilities for rapid and highly sensitive diagnostics at the point of care. 

Place, publisher, year, edition, pages
American Chemical Society, 2020
Keywords
binding kinetics, Brownian relaxation, homogeneous differential magnetic assay, magnetic nanoparticle, rolling circle amplification, volumetric detection, Amplification, Molecules, Nanoparticles, Brownian relaxations, Magnetic nano-particles, Rolling circle amplifications, Nanomagnetics
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39981 (URN)10.1021/acssensors.9b00969 (DOI)
Note

Funding details: Vetenskapsrådet, VR, 2015-03640; Funding details: Stiftelsen för Strategisk Forskning, SSF; Funding details: Stiftelsen för Strategisk Forskning, SSF, SBE13-0125; Funding details: Knut och Alice Wallenbergs Stiftelse; Funding text 1: S.S., J.F.S, A.K., and D.W. conceived and designed the experiments. S.S. conducted the experiments and analyzed the data. T.Z.G.d.l.T. contributed with the biochemical processes. A.J. helped with the fabrication of the microfluidics. J.B. performed reference ac susceptibility measurements and contributed in the discussion of the initial results. C.J. contributed in the discussion of the results and analysis. S.S. and A.K. drafted the manuscript. All authors reviewed the manuscript and provided comments. This work was supported through the Swedish Foundation for Strategic Research (SSF) Grant “FLU-ID” No. SBE13-0125, the Swedish Research Council Grant 2015-03640, the Knut and Alice Wallenberg Foundation, and the Swedish Infrastructure for Micro- and Nanofabrication–Myfab. The authors declare the following competing financial interest(s): S.S., A.K., and D.W. are co-inventors of a patent filed on the subject of this work. The other authors declare no competing interests.

Available from: 2019-10-09 Created: 2019-10-09 Last updated: 2019-10-09Bibliographically approved
Sepehri, S., Agnarsson, B., Torre, T., Schneiderman, J., Blomgren, J., Jesorka, A., . . . Kalaboukhov, A. (2019). Characterization of Binding of Magnetic Nanoparticles to Rolling Circle Amplification Products by Turn-On Magnetic Assay. Biosensors, 9(3)
Open this publication in new window or tab >>Characterization of Binding of Magnetic Nanoparticles to Rolling Circle Amplification Products by Turn-On Magnetic Assay
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2019 (English)In: Biosensors, ISSN 2079-6374, Vol. 9, no 3Article in journal (Refereed) Published
Abstract [en]

The specific binding of oligonucleotide-tagged 100 nm magnetic nanoparticles (MNPs) to rolling circle products (RCPs) is investigated using our newly developed differential homogenous magnetic assay (DHMA). The DHMA measures ac magnetic susceptibility from a test and a control samples simultaneously and eliminates magnetic background signal. Therefore, the DHMA can reveal details of binding kinetics of magnetic nanoparticles at very low concentrations of RCPs. From the analysis of the imaginary part of the DHMA signal, we find that smaller MNPs in the particle ensemble bind first to the RCPs. When the RCP concentration increases, we observe the formation of agglomerates, which leads to lower number of MNPs per RCP at higher concentrations of RCPs. The results thus indicate that a full frequency range of ac susceptibility observation is necessary to detect low concentrations of target RCPs and a long amplification time is not required as it does not significantly increase the number of MNPs per RCP. The findings are critical for understanding the underlying microscopic binding process for improving the assay performance. They furthermore suggest DHMA is a powerful technique for dynamically characterizing the binding interactions between MNPs and biomolecules in fluid volumes.

Place, publisher, year, edition, pages
NLM (Medline), 2019
Keywords
binding kinetics, bioassay, differential homogenous magnetic assay, immobilization, magnetic nanoparticle, rolling circle amplification product
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39975 (URN)10.3390/bios9030109 (DOI)s2.0-85072380802 (Scopus ID)
Available from: 2019-10-10 Created: 2019-10-10 Last updated: 2019-10-10Bibliographically approved
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)2-s2.0-85070086254 (Scopus ID)
Conference
2019/08/08
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-10-17Bibliographically approved
Baresel, C., Schaller, V., Jonasson, C., Johansson, C., Bordes, R., Chauhan, V., . . . Welling, S. (2019). Functionalized magnetic particles for water treatment. Heliyon, 5(8), Article ID e02325.
Open this publication in new window or tab >>Functionalized magnetic particles for water treatment
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2019 (English)In: Heliyon, ISSN 2405-8440, Vol. 5, no 8, article id e02325Article in journal (Refereed) Published
Abstract [en]

In this study, we have taken the concept of water treatment by functionalized magnetic particles one step forward by integrating the technology into a complete proof of concept, which included the preparation of surface modified beads, their use as highly selective absorbents for heavy metals ions (Zinc, Nickel), and their performance in terms of magnetic separation. The separation characteristics were studied both through experiments and by simulations. The data gathered from these experimental works enabled the elaboration of various scenarios for Life Cycle Analysis (LCA). The LCA showed that the environmental impact of the system is highly dependent on the recovery rate of the magnetic particles. The absolute impact on climate change varied significantly among the scenarios studied and the recovery rates. The results support the hypothesis that chelation specificity, magnetic separation and bead recovery should be optimized to specific targets and applications. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2019
Keywords
Chemical engineering, Environmental science, Life cycle assessment, Magnetic particle, Materials chemistry, Nanotechnology, Pollutant, Water treatment
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39844 (URN)10.1016/j.heliyon.2019.e02325 (DOI)2-s2.0-85070906522 (Scopus ID)
Note

This work was supported by VINNOVA , the Swedish Governmental Agency for Innovation, within the call Innovationer för ett hållbart samhälle: miljö och transport.

Available from: 2019-10-01 Created: 2019-10-01 Last updated: 2019-10-17Bibliographically approved
Jonasson, C., Schaller, V., Zeng, L., Olsson, E., Frandsen, C., Castro, A., . . . Johansson, C. (2019). Modelling the effect of different core sizes and magnetic interactions inside magnetic nanoparticles on hyperthermia performance. Journal of Magnetism and Magnetic Materials, 477, 198-202
Open this publication in new window or tab >>Modelling the effect of different core sizes and magnetic interactions inside magnetic nanoparticles on hyperthermia performance
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2019 (English)In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 477, p. 198-202Article in journal (Refereed) Published
Abstract [en]

We present experimental intrinsic loss power (ILP) values, measured at an excitation frequency of 1 MHz and at relatively low field amplitudes of 3.4 to 9.9 kA/m, as a function of the mean core diameter, for selected magnetic nanoparticle (MNP). The mean core sizes ranged from ca. 8 nm to 31 nm. Transmission electron microscopy indicated that those with smaller core sizes (less than ca. 22 nm) were single-core MNPs, while those with larger core sizes (ca. 29 nm to 31 nm) were multi-core MNPs. The ILP data showed a peak at ca. 20 nm. We show here that this behaviour correlates well with the predicted ILP values obtained using either a non-interacting Debye model, or via dynamic Monte-Carlo simulations, the latter including core-core magnetic interactions for the multi-core particles. This alignment of the models is a consequence of the low field amplitudes used. We also present interesting results showing that the core-core interactions affect the ILP value differently depending on the mean core size.

Keywords
magnetic nanoparticles, magnetic interactions, magnetic relaxation, Monte-Carlo simulations, multi-core particles, single-core particles
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36361 (URN)10.1016/j.jmmm.2018.09.117 (DOI)2-s2.0-85060279115 (Scopus ID)
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2019-10-17Bibliographically 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

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: 2019-10-17Bibliographically approved
Elmquist, L., Carlsson, R. & Johansson, C. (2018). Cast iron components with intelligence. In: : . Paper presented at Mater. Sci. Forum. 4 September 2017 through 7 September 2017 (pp. 512-519). , 925
Open this publication in new window or tab >>Cast iron components with intelligence
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The paper describes a project with the aim to develop communicating and functional cast iron components in smart systems. The concept is based on sensors integrated into cast iron components; this will influence not only the component but also the casting process. Among the technical challenges is how to choose a sensor solution that cost-efficiently and with minimal environmental impact can be integrated into the component during the casting process, and especially without being damaged during mold filling and the high pouring temperature. Another challenge is how the iron will interact and interfere with sensor signals and whether an insulating intermediate material is needed or not. Integrating the sensors into the casting makes sensors a natural part of the component, which in turn can lead to more resource efficient designs, increased value added for the casting sector, and a general access to different possibilities of digitalization. The integrated sensors can be used for effective control and monitoring of components when in service and give information about for example how the component is used and what conditions it is exposed to. In other words, the component can tell when maintenance is needed or in worst cases, indicate that something is wrong before a failure will happen. Important measurands can e.g. be elongation, shear, temperature and vibration. Different combinations of sensor materials and insulating materials and their interaction with the cast iron have been investigated. It is shown how the interaction at the interface affects the microstructure and consequently the properties of the cast iron. In the case of insulating materials it is e.g. shown how air gaps are formed and in the case of sensor materials it is shown how a diffusion zone is formed and how this zone depends on the sensor material. How this diffusion zone affects the microstructure is discussed.

Keywords
Cast iron, Digitalized castings, Integrated sensors, Intelligent cast components, Intelligent castings, Interfacial phenomena, Environmental impact, Insulating materials, Insulation, Microstructure, Molds, Cast components, Control and monitoring, Intermediate materials, Pouring temperatures, Technical challenges, Without being damaged
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34469 (URN)10.4028/www.scientific.net/MSF.925.512 (DOI)2-s2.0-85050011551 (Scopus ID)9783035710557 (ISBN)
Conference
Mater. Sci. Forum. 4 September 2017 through 7 September 2017
Note

Funding details: VINNOVA;

Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2019-06-27Bibliographically approved
Wetterskog, E., Jonasson, C., Smilgies, D.-M., Schaller, V., Johansson, C. & Svedlindh, P. (2018). Colossal Anisotropy of the Dynamic Magnetic Susceptibility in Low-Dimensional Nanocube Assemblies. ACS Nano, 12(2), 1403-1412
Open this publication in new window or tab >>Colossal Anisotropy of the Dynamic Magnetic Susceptibility in Low-Dimensional Nanocube Assemblies
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2018 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 2, p. 1403-1412Article in journal (Refereed) Submitted
Abstract [en]

nanocubes display a significant augmentation of the magnetic susceptibility and dissipation as compared to 0D and 2D systems. The performance of the nanocube needles is highlighted by a colossal anisotropy factor defined as the ratio of the parallel to the perpendicular magnetization components. We show that the origin of this effect cannot be ascribed to shape anisotropy in its classical sense; as such, it has no analogy in bulk magnetic materials. The temperature-dependent anisotropy factors of the in- and out-of-phase components of the magnetization have an extremely strong particle size dependence and reach values of 80 and 2500, respectively, for the largest nanocubes in this study. Aided by simulations, we ascribe the anisotropy of the magnetic susceptibility, and its strong particle-size dependence to a synergistic coupling between the dipolar interaction field and a net anisotropy field resulting from a partial texture in the 1D nanocube needles.

Keywords
ac-susceptibility, anisotropy, arrays, assemblies, magnetic nanoparticles, magnetic properties, supercrystals
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33343 (URN)10.1021/acsnano.7b07745 (DOI)29328678 (PubMedID)2-s2.0-85042705323 (Scopus ID)
Available from: 2018-02-28 Created: 2018-02-28 Last updated: 2019-10-17Bibliographically approved
Carlsson, R., Elmquist, L., Thore, A., Ahrentorp, F., Johansson, C. & Israelsson, B. (2018). Connecting sensors inside smart castings. In: : . Paper presented at 7 th International Symposium on Aircraft Materials (ACMA2018) April 24-26, 2018, Compiègne (France).
Open this publication in new window or tab >>Connecting sensors inside smart castings
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The paper presents ongoing research on smart metal castings, meaning the technologicalinnovation of elevating cast metal components into metal components with integratedsensor functionality. Since the innovation targets aim straight at low cost industrial serialproduction, specific high cost and high-end solutions like inclusion of advancedelectronic equipment and after mounted sensors are not part of this innovationdevelopment. Integrating signal carriers inside metal castings to achieve metal castingswith sensor functionality requires robust solutions for connecting the sensor signal to thesensor interrogator and interpreter. The actual transmission of the signal may be donewirelessly or by wire. However, for several reasons there is a challenge with establishingan isolated and distinct connection between the sensor contact, and the contact at theexternal connection, regardless of whether it is to an antenna for wireless transmission orto a wire. This paper presents metallurgical challenges associated with choices ofmaterials, and combinations of metallurgical challenges and production process relatedchallenges, including the high melting temperatures. Aims are to find the rightcombinations of metal alloys, production simplicity, signal stability and robustness. Thepaper will present some of the tests made in the project so far. The project is run in aconsortium of the two Sweden-based industrial companies Husqvarna and SKF, and thetwo Swedish research institutes Swerea SWECAST and RISE Acreo.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34921 (URN)
Conference
7 th International Symposium on Aircraft Materials (ACMA2018) April 24-26, 2018, Compiègne (France)
Available from: 2018-08-23 Created: 2018-08-23 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.

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: 2019-10-17Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6662-8023

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