1
|
Liu CW, Tsutsui H. Sample-to-answer sensing technologies for nucleic acid preparation and detection in the field. SLAS Technol 2023; 28:302-323. [PMID: 37302751 DOI: 10.1016/j.slast.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/16/2023] [Accepted: 06/06/2023] [Indexed: 06/13/2023]
Abstract
Efficient sample preparation and accurate disease diagnosis under field conditions are of great importance for the early intervention of diseases in humans, animals, and plants. However, in-field preparation of high-quality nucleic acids from various specimens for downstream analyses, such as amplification and sequencing, is challenging. Thus, developing and adapting sample lysis and nucleic acid extraction protocols suitable for portable formats have drawn significant attention. Similarly, various nucleic acid amplification techniques and detection methods have also been explored. Combining these functions in an integrated platform has resulted in emergent sample-to-answer sensing systems that allow effective disease detection and analyses outside a laboratory. Such devices have a vast potential to improve healthcare in resource-limited settings, low-cost and distributed surveillance of diseases in food and agriculture industries, environmental monitoring, and defense against biological warfare and terrorism. This paper reviews recent advances in portable sample preparation technologies and facile detection methods that have been / or could be adopted into novel sample-to-answer devices. In addition, recent developments and challenges of commercial kits and devices targeting on-site diagnosis of various plant diseases are discussed.
Collapse
Affiliation(s)
- Chia-Wei Liu
- Department of Mechanical Engineering, University of California, Riverside, CA 92521, USA
| | - Hideaki Tsutsui
- Department of Mechanical Engineering, University of California, Riverside, CA 92521, USA; Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| |
Collapse
|
2
|
Ivanov AO, Camp PJ. Magnetization relaxation dynamics in polydisperse ferrofluids. Phys Rev E 2023; 107:034604. [PMID: 37072981 DOI: 10.1103/physreve.107.034604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/13/2023] [Indexed: 04/20/2023]
Abstract
When a ferrofluid is magnetized in a strong magnetic field, and then the field is switched off, the magnetization decays from its saturation value to zero. The dynamics of this process are controlled by the rotations of the constituent magnetic nanoparticles, and for the Brownian mechanism, the respective rotation times are strongly influenced by the particle size and the magnetic dipole-dipole interactions between the particles. In this work, the effects of polydispersity and interactions on the magnetic relaxation are studied using a combination of analytical theory and Brownian dynamics simulations. The theory is based on the Fokker-Planck-Brown equation for Brownian rotation and includes a self-consistent, mean-field treatment of the dipole-dipole interactions. The most interesting predictions from the theory are that, at short times, the relaxation of each particle type is equal to its intrinsic Brownian rotation time, while at long times, each particle type has the same effective relaxation time, which is longer than any of the individual Brownian rotation times. Noninteracting particles, though, always relax at a rate controlled only by the Brownian rotation times. This illustrates the importance of including the effects of polydispersity and interactions when analyzing the results from magnetic relaxometry experiments on real ferrofluids, which are rarely monodisperse.
Collapse
Affiliation(s)
- Alexey O Ivanov
- Department of Theoretical and Mathematical Physics, Ural Mathematical Center, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Philip J Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland
| |
Collapse
|
3
|
Ludwig F, Remmer H. Rotational dynamics of magnetic nanoparticles in different matrix systems. PHYSICAL SCIENCES REVIEWS 2022. [DOI: 10.1515/psr-2019-0115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Abstract
Dynamic magnetic measurements on magnetic nanoparticle (MNP) samples have been widely used for the determination of structural MNP parameters as well as for the realization of bioassays. On the other hand, proposed that the MNPs are thermally blocked, i.e., that the dynamics are dominated by the Brownian rotation, and knowing the distribution of their hydrodynamic size, information on the matrix properties can be obtained. In contrast to conventional rheology, the local environment of the MNPs is sensed on the nanoscale so that important information on the embedding of MNPs in the matrix and thus the particle-matrix interaction is obtained. Depending on the characteristic length scales of the matrix and the size of the MNPs, rheological parameters, such as viscosity and shear modulus, derived from nanorheological measurements can differ from the values obtained from conventional rheology. To measure the MNP dynamics, different experimental techniques can be applied. In this contribution, the focus lies on ac susceptometry and fluxgate magnetorelaxometry. The analysis of the complex ACS spectra is generally carried out within a modified Debye model. Different approaches for the estimation of rheological parameters from the complex ACS spectra will be presented. Two model systems will exemplarily be discussed in detail. As a Newtonian matrix system, water-glycerol mixtures were studied. It is demonstrated that the dynamic viscosity can accurately be estimated from ACS measurements on well thermally blocked single-core as well as on multicore MNP systems, which include Brownian and Néel dynamics. As a viscoelastic matrix system, aqueous gelatin solutions were studied. Gelatin is known to be a Voigt-Kelvin model system, in which elastic and viscous forces are parallel. In particular, we studied the gelation dynamics by repetitive measurements of the complex ACS spectrum. Different approaches to derive viscosity and shear modulus are applied and compared. In order to identify magnetoviscous effects in dynamic magnetic measurements, the magnetic field dependence of the Brownian relaxation time has to be eliminated. ACS measurements on various sufficiently strongly diluted aqueous MNP suspensions were performed in dependence of ac field amplitude and superimposed dc field strength and compared to theory. Excellent agreement was found.
Collapse
Affiliation(s)
- Frank Ludwig
- Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik , TU Braunschweig , D-38106 Braunschweig , Germany
| | - Hilke Remmer
- Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik , TU Braunschweig , D-38106 Braunschweig , Germany
| |
Collapse
|
4
|
Xiao X, Yuan C, Li T, Fock J, Svedlindh P, Tian B. Optomagnetic biosensors: Volumetric sensing based on magnetic actuation-induced optical modulations. Biosens Bioelectron 2022; 215:114560. [PMID: 35841765 DOI: 10.1016/j.bios.2022.114560] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 04/25/2022] [Accepted: 07/07/2022] [Indexed: 12/19/2022]
Abstract
In comparison to alternative nanomaterials, magnetic micron/nano-sized particles show unique advantages, e.g., easy manipulation, stable signal, and high contrast. By applying magnetic actuation, magnetic particles exert forces on target objects for highly selective operation even in non-purified samples. We herein describe a subgroup of magnetic biosensors, namely optomagnetic biosensors, which employ alternating magnetic fields to generate periodic movements of magnetic labels. The optical modulation induced by the dynamics of magnetic labels is then analyzed by photodetectors, providing information of, e.g., hydrodynamic size changes of the magnetic labels. Optomagnetic sensing mechanisms can suppress the noise (by performing lock-in detection), accelerate the reaction (by magnetic force-enhanced molecular collision), and facilitate homogeneous/volumetric detection. Moreover, optomagnetic sensing can be performed using a low magnetic field (<10 mT) without sophisticated light sources or pickup coils, further enhancing its applicability for point-of-care tests. This review concentrates on optomagnetic biosensing techniques of different concepts classified by the magnetic actuation strategy, i.e., magnetic field-enhanced agglutination, rotating magnetic field-based particle rotation, and oscillating magnetic field-induced Brownian relaxation. Optomagnetic sensing principles applied with different actuation strategies are introduced as well. For each representative optomagnetic biosensor, a simple immunoassay strategy-based application is introduced (if possible) for methodological comparison. Thereafter, challenges and perspectives are discussed, including minimization of nonspecific binding, on-chip integration, and multiplex detection, all of which are key requirements in point-of-care diagnostics.
Collapse
Affiliation(s)
- Xiaozhou Xiao
- Department of Biomedical Engineering, School of Basic Medical Science, Central South University, Changsha Hunan, 410013, China
| | - Chuqi Yuan
- Department of Biomedical Engineering, School of Basic Medical Science, Central South University, Changsha Hunan, 410013, China
| | - Tingting Li
- Department of Biomedical Engineering, School of Basic Medical Science, Central South University, Changsha Hunan, 410013, China
| | - Jeppe Fock
- Blusense Diagnostics ApS, Fruebjergvej 3, DK-2100, Copenhagen, Denmark
| | - Peter Svedlindh
- Department of Materials Science and Engineering, Uppsala University, Box 35, SE-751 03, Uppsala, Sweden
| | - Bo Tian
- Department of Biomedical Engineering, School of Basic Medical Science, Central South University, Changsha Hunan, 410013, China.
| |
Collapse
|
5
|
Ivanov AO, Camp PJ. Effects of interactions, structure formation, and polydispersity on the dynamic magnetic susceptibility and magnetic relaxation of ferrofluids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
6
|
Rusanov MS, Zverev VS, Elfimova EA. Dynamic magnetic susceptibility of a ferrofluid: The influence of interparticle interactions and ac field amplitude. Phys Rev E 2021; 104:044604. [PMID: 34781481 DOI: 10.1103/physreve.104.044604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/20/2021] [Indexed: 11/07/2022]
Abstract
Based on numerical results of dynamic susceptibility, a simple theory of the dynamic response of a ferrofluid to an ac magnetic field is obtained that includes both the effects of interparticle dipole-dipole interactions and the dependence on field amplitude. Interparticle interactions are incorporated in the theory using the so-called modified mean-field approach. The new theory has the following important characteristics: in the noninteracting regime at a weak ac field, it gives the correct single-particle Debye theory results; it expands the applicability of known theories valid for high concentrations [Ivanov, Zverev, and Kantorovich, Soft Matter 12, 3507 (2016)10.1039/C5SM02679B] or large values of ac field amplitudes [Yoshida and Enpuku, Jpn. J. Appl. Phys. 48, 127002 (2009)10.1143/JJAP.48.127002], in accordance with their applicability. The susceptibility spectra are analyzed in detail. It is demonstrated that interparticle dipole-dipole interactions and an increase in field amplitude have an opposite effect on the dynamic response of ferrofluids, so that at certain field amplitudes, relaxation processes in the system of interacting particles are determined by the characteristic relaxation times for an ideal paramagnetic gas. The new theory correctly predicts the dynamic susceptibility and characteristic relaxation times of a ferrofluid at high ac field amplitudes as long as the Langevin susceptibility χ_{L}≲1, which is a complex characteristic of ferrofluid density and the intensity of interparticle dipole-dipole interactions.
Collapse
Affiliation(s)
- Michael S Rusanov
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Vladimir S Zverev
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Ekaterina A Elfimova
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| |
Collapse
|
7
|
Oropesa-Nuñez R, Zardán Gómez de la Torre T, Stopfel H, Svedlindh P, Strömberg M, Gunnarsson K. Insights into the Formation of DNA-Magnetic Nanoparticle Hybrid Structures: Correlations between Morphological Characterization and Output from Magnetic Biosensor Measurements. ACS Sens 2020; 5:3510-3519. [PMID: 33141554 PMCID: PMC7706118 DOI: 10.1021/acssensors.0c01623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Understanding
the binding mechanism between probe-functionalized
magnetic nanoparticles (MNPs) and DNA targets or amplification products
thereof is essential in the optimization of magnetic biosensors for
the detection of DNA. Herein, the molecular interaction forming hybrid
structures upon hybridization between DNA-functionalized magnetic
nanoparticles, exhibiting Brownian relaxation, and rolling circle
amplification products (DNA-coils) is investigated by the use of atomic
force microscopy in a liquid environment and magnetic biosensors measuring
the frequency-dependent magnetic response and the frequency-dependent
modulation of light transmission. This approach reveals the qualitative
and quantitative correlations between the morphological features of
the hybrid structures with their magnetic response. The suppression
of the high-frequency peak in the magnetic response and the appearance
of a new peak at lower frequencies match the formation of larger sized
assemblies upon increasing the concentration of DNA-coils. Furthermore,
an increase of the DNA-coil concentration induces an increase in the
number of MNPs per hybrid structure. This study provides new insights
into the DNA–MNP binding mechanism, and its versatility is
of considerable importance for the mechanistic characterization of
other DNA-nanoparticle biosensor systems.
Collapse
Affiliation(s)
- Reinier Oropesa-Nuñez
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| | - Teresa Zardán Gómez de la Torre
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| | - Henry Stopfel
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| | - Peter Svedlindh
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| | - Mattias Strömberg
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| | - Klas Gunnarsson
- Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Box 35, SE-751 03 Uppsala, Sweden
| |
Collapse
|
8
|
Ivanov AO, Camp PJ. Effects of interactions on magnetization relaxation dynamics in ferrofluids. Phys Rev E 2020; 102:032610. [PMID: 33075873 DOI: 10.1103/physreve.102.032610] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/01/2020] [Indexed: 11/07/2022]
Abstract
The dynamics of magnetization relaxation in ferrofluids are studied with statistical-mechanical theory and Brownian dynamics simulations. The particle dipole moments are initially perfectly aligned, and the magnetization is equal to its saturation value. The magnetization is then allowed to decay under zero-field conditions toward its equilibrium value of zero. The time dependence is predicted by solving the Fokker-Planck equation for the one-particle orientational distribution function. Interactions between particles are included by introducing an effective magnetic field acting on a given particle and arising from all of the other particles. Two different approximations are proposed and tested against simulations: a first-order modified mean-field theory and a modified Weiss model. The theory predicts that the short-time decay is characterized by the Brownian rotation time τ_{B}, independent of the interaction strength. At times much longer than τ_{B}, the asymptotic decay time is predicted to grow with increasing interaction strength. These predictions are borne out by the simulations. The modified Weiss model gives the best agreement with simulation, and its range of validity is limited to moderate, but realistic, values of the dipolar coupling constant.
Collapse
Affiliation(s)
- Alexey O Ivanov
- Department of Theoretical and Mathematical Physics, Ural Mathematical Center, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Philip J Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland and Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| |
Collapse
|
9
|
Tian B, Gao F, Fock J, Dufva M, Hansen MF. Homogeneous circle-to-circle amplification for real-time optomagnetic detection of SARS-CoV-2 RdRp coding sequence. Biosens Bioelectron 2020; 165:112356. [PMID: 32510339 DOI: 10.1016/j.bios.2020.112356] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/28/2020] [Accepted: 06/01/2020] [Indexed: 12/21/2022]
Abstract
Circle-to-circle amplification (C2CA) is a specific and precise cascade nucleic acid amplification method consisting of more than one round of padlock probe ligation and rolling circle amplification (RCA). Although C2CA provides a high amplification efficiency with a negligible increase of false-positive risk, it contains several step-by-step operation processes. We herein demonstrate a homogeneous and isothermal nucleic acid quantification strategy based on C2CA and optomagnetic analysis of magnetic nanoparticle (MNP) assembly. The proposed homogeneous circle-to-circle amplification eliminates the need for additional monomerization and ligation steps after the first round of RCA, and combines two amplification rounds in a one-pot reaction. The second round of RCA produces amplicon coils that anneal to detection probes grafted onto MNPs, resulting in MNP assembly that can be detected in real-time using an optomagnetic sensor. The proposed methodology was applied for the detection of a synthetic complementary DNA of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2, also known as 2019-nCoV) RdRp (RNA-dependent RNA polymerase) coding sequence, achieving a detection limit of 0.4 fM with a dynamic detection range of 3 orders of magnitude and a total assay time of ca. 100 min. A mathematical model was set up and validated to predict the assay performance. Moreover, the proposed method was specific to distinguish SARS-CoV and SARS-CoV-2 sequences with high similarity.
Collapse
Affiliation(s)
- Bo Tian
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark.
| | - Fei Gao
- Department of Physics, Technical University of Denmark, DTU Physics, Building 307, DK-2800, Kongens Lyngby, Denmark
| | - Jeppe Fock
- Blusense Diagnostics ApS, Fruebjergvej 3, DK-2100, Copenhagen, Denmark
| | - Martin Dufva
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark
| | - Mikkel Fougt Hansen
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark.
| |
Collapse
|
10
|
Tian B, Fock J, Minero GAS, Hansen MF. Nicking-assisted on-loop and off-loop enzymatic cascade amplification for optomagnetic detection of a highly conserved dengue virus sequence. Biosens Bioelectron 2020; 160:112219. [PMID: 32339155 DOI: 10.1016/j.bios.2020.112219] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 12/11/2022]
Abstract
Applications of conventional linear ligation-rolling circle amplification (RCA) are restricted by the sophisticated operation steps and unsatisfactory picomolar-level detection limits. We herein demonstrate an RCA-based cascade amplification reaction that converts a side-reaction to secondary amplification, which improves the detection limit and simplifies the operation compared to linear ligation-RCA assays. The proposed nicking-assisted enzymatic cascade amplification (NECA) comprises an on-loop amplification reaction using circular templates to generate intermediate amplicons, and an off-loop amplification reaction using intermediate amplicons as primers for end amplicons. The whole NECA reaction is homogeneous and isothermal. Amplicons anneal to detection probes that are grafted onto magnetic nanoparticles (MNPs), such that MNP clusters form and can be detected in real-time using optomagnetic measurements. The optomagnetic sensor detects the presence and size increase of MNP clusters by optical transmission measurements in an oscillating magnetic field. A detection limit of 2 fM was achieved with a total assay time of ca. 70 min. By combining optomagnetic readouts of signal phase lag and hydrodynamic size increase of MNPs, NECA-based target quantification provided a wide dynamic detection range of ca. 4.5 orders of magnitude. Moreover, the specificity and the serum detection capability of the proposed method were investigated.
Collapse
Affiliation(s)
- Bo Tian
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark.
| | - Jeppe Fock
- Blusense Diagnostics ApS, Fruebjergvej 3, DK-2100, Copenhagen, Denmark
| | - Gabriel Antonio S Minero
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark
| | - Mikkel Fougt Hansen
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800, Kongens Lyngby, Denmark.
| |
Collapse
|
11
|
Tian B, Minero G, Fock J, Dufva M, Hansen MF. CRISPR-Cas12a based internal negative control for nonspecific products of exponential rolling circle amplification. Nucleic Acids Res 2020; 48:e30. [PMID: 31956898 PMCID: PMC7049689 DOI: 10.1093/nar/gkaa017] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/16/2019] [Accepted: 01/03/2020] [Indexed: 12/26/2022] Open
Abstract
False-positive results cause a major problem in nucleic acid amplification, and require external blank/negative controls for every test. However, external controls usually have a simpler and lower background compared to the test sample, resulting in underestimation of false-positive risks. Internal negative controls, performed simultaneously with amplification to monitor the background level in real-time, are therefore appealing in both research and clinic. Herein, we describe a nonspecific product-activated single-stranded DNA-cutting approach based on CRISPR (clustered regularly interspaced short palindromic repeats) Cas12a (Cpf1) nuclease. The proposed approach, termed Cas12a-based internal referential indicator (CIRI), can indicate the onset of nonspecific amplification in an exponential rolling circle amplification strategy here combined with an optomagnetic readout. The capability of CIRI as an internal negative control can potentially be extended to other amplification strategies and sensors, improving the performance of nucleic acid amplification-based methodologies.
Collapse
Affiliation(s)
- Bo Tian
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800 Kongens Lyngby, Denmark
| | - Gabriel Antonio S Minero
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800 Kongens Lyngby, Denmark
| | - Jeppe Fock
- Blusense Diagnostics ApS, Fruebjergvej 3, DK-2100 Copenhagen, Denmark
| | - Martin Dufva
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800 Kongens Lyngby, Denmark
| | - Mikkel Fougt Hansen
- Department of Health Technology, Technical University of Denmark, DTU Health Tech, Building 345C, DK-2800 Kongens Lyngby, Denmark
| |
Collapse
|
12
|
Elfimova EA, Ivanov AO, Camp PJ. Static magnetization of immobilized, weakly interacting, superparamagnetic nanoparticles. NANOSCALE 2019; 11:21834-21846. [PMID: 31696187 DOI: 10.1039/c9nr07425b] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The magnetization curve and initial susceptibility of immobilized superparamagnetic nanoparticles are studied using statistical-mechanical theory and Monte Carlo computer simulations. The nanoparticles are considered to be distributed randomly within an implicit solid matrix, but with the easy axes distributed according to particular textures: these are aligned parallel or perpendicular to an external magnetic field, or randomly distributed. The magnetic properties are calculated as functions of the magnetic crystallographic anisotropy barrier (measured with respect to the thermal energy by a parameter σ), and the Langevin susceptibility (related to the dipolar coupling constant and the volume fraction). It is shown that the initial susceptibility χ is independent of σ in the random case, an increasing function of σ in the parallel case, and a decreasing function of σ in the perpendicular case. Including particle-particle interactions enhances χ, and especially so in the parallel case. A first-order modified mean-field (MMF1) theory is accurate as compared to the simulation results, except in the parallel case with a large value of σ. These observations can be explained in terms of the range and strength of the (effective) interactions and correlations between particles, and the effects of the orientational degrees of freedom. The full magnetization curves show that a parallel texture enhances the magnetization, while a perpendicular texture suppresses it, with the effects growing with increasing σ. In the random case, while the initial response is independent of σ, the high-field magnetization decreases with increasing σ. These trends can be explained by the energy required to rotate the magnetic moments with respect to the easy axes.
Collapse
Affiliation(s)
- Ekaterina A Elfimova
- Ural Federal University, 51 Lenin Avenue, 620000 Ekaterinburg, Russian Federation.
| | | | | |
Collapse
|
13
|
Optomagnetic Detection of Rolling Circle Amplification Products. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2019; 2063:3-15. [PMID: 31667758 DOI: 10.1007/978-1-0716-0138-9_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Rolling circle amplification (RCA) of a synthetic nucleic acid target is detected using magnetic nanoparticles (MNPs) combined with an optomagnetic (OM) readout. Two RCA assays are developed with on-chip detection of rolling circle products (RCPs) either at end-point where MNPs are mixed with the sample after completion of RCA or in real time where MNPs are mixed with the sample during RCA. The plastic chip acts as a cuvette, which is positioned in a setup integrated with temperature control and simultaneous detection of four parallel DNA hybridization reactions between functionalized MNPs and products of DNA amplification. The OM technique probes the small-angle rotation of MNPs bearing oligonucleotide probes complementary to the repeated nucleotide sequence of the RCPs. This rotation is restricted when MNPs bind to RCPs, which can be observed as a turn-off of the signal from MNPs that are free to rotate. The amount of MNPs bound to RCPs is found to increase in response to the amplification time as well as in response to the synthetic DNA target concentration (2-40 pM dynamic range). We report OM real-time results obtained with MNPs present during RCA and compare to relevant end-point OM results for RCPs generated for different RCA times. The real-time approach avoids opening of tubes post-RCA and thus reduces risk of lab contamination with amplification products without compromising the sensitivity and dynamic range of the assay.
Collapse
|
14
|
Garbarino F, Minero GAS, Rizzi G, Fock J, Hansen MF. Integration of rolling circle amplification and optomagnetic detection on a polymer chip. Biosens Bioelectron 2019; 142:111485. [DOI: 10.1016/j.bios.2019.111485] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 01/14/2023]
|
15
|
Minero GAS, Cangiano V, Garbarino F, Fock J, Hansen MF. Integration of microbead DNA handling with optomagnetic detection in rolling circle amplification assays. Mikrochim Acta 2019; 186:528. [DOI: 10.1007/s00604-019-3636-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/25/2019] [Indexed: 01/14/2023]
|
16
|
Ultrasensitive Real-Time Rolling Circle Amplification Detection Enhanced by Nicking-Induced Tandem-Acting Polymerases. Anal Chem 2019; 91:10102-10109. [DOI: 10.1021/acs.analchem.9b02073] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
17
|
Landers J, Salamon S, Remmer H, Ludwig F, Wende H. In-Field Orientation and Dynamics of Ferrofluids Studied by Mössbauer Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2019; 11:3160-3168. [PMID: 30582794 DOI: 10.1021/acsami.8b16356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
By studying the response behavior of ferrofluids of 6-22 nm maghemite nanoparticles in glycerol solution exposed to external magnetic fields, we demonstrate the ability of Mössbauer spectroscopy to access a variety of particle dynamics and static magnetic particle characteristics at the same time, offering an extensive characterization of ferrofluids for in-field applications; field-dependent particle alignment and particle mobility in terms of Brownian motion have been extracted simultaneously from a series of Mössbauer spectra for single-core particles as well as for particle agglomerates. Additionally, information on Néel superspin relaxation and surface spin frustration could be directly inferred from this analysis. Parameters regarding Brownian particle dynamics, as well as Néel-type relaxation behavior, obtained via Mössbauer spectroscopy, have been verified by complementary AC-susceptometry experiments, modulating the AC-field amplitude, and using an extended frequency range of 10-1 to 106 Hz, while field-dependent particle alignment has been cross-checked via magnetometry.
Collapse
Affiliation(s)
- Joachim Landers
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) , University of Duisburg-Essen , Lotharstr. 1 , 47057 Duisburg , Germany
| | - Soma Salamon
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) , University of Duisburg-Essen , Lotharstr. 1 , 47057 Duisburg , Germany
| | - Hilke Remmer
- Institute for Electrical Measurement Science and Fundamental Electrical Engineering , TU Braunschweig , Hans-Sommer-Straße 66 , 38106 Braunschweig , Germany
| | - Frank Ludwig
- Institute for Electrical Measurement Science and Fundamental Electrical Engineering , TU Braunschweig , Hans-Sommer-Straße 66 , 38106 Braunschweig , Germany
| | - Heiko Wende
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) , University of Duisburg-Essen , Lotharstr. 1 , 47057 Duisburg , Germany
| |
Collapse
|
18
|
Bender P, Fock J, Hansen MF, Bogart LK, Southern P, Ludwig F, Wiekhorst F, Szczerba W, Zeng LJ, Heinke D, Gehrke N, Díaz MTF, González-Alonso D, Espeso JI, Fernández JR, Johansson C. Influence of clustering on the magnetic properties and hyperthermia performance of iron oxide nanoparticles. NANOTECHNOLOGY 2018; 29:425705. [PMID: 30052525 DOI: 10.1088/1361-6528/aad67d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Clustering of magnetic nanoparticles can drastically change their collective magnetic properties, which in turn may influence their performance in technological or biomedical applications. Here, we investigate a commercial colloidal dispersion (FeraSpinTMR), which contains dense clusters of iron oxide cores (mean size around 9 nm according to neutron diffraction) with varying cluster size (about 18-56 nm according to small angle x-ray diffraction), and its individual size fractions (FeraSpinTMXS, S, M, L, XL, XXL). The magnetic properties of the colloids were characterized by isothermal magnetization, as well as frequency-dependent optomagnetic and AC susceptibility measurements. From these measurements we derive the underlying moment and relaxation frequency distributions, respectively. Analysis of the distributions shows that the clustering of the initially superparamagnetic cores leads to remanent magnetic moments within the large clusters. At frequencies below 105 rad s-1, the relaxation of the clusters is dominated by Brownian (rotation) relaxation. At higher frequencies, where Brownian relaxation is inhibited due to viscous friction, the clusters still show an appreciable magnetic relaxation due to internal moment relaxation within the clusters. As a result of the internal moment relaxation, the colloids with the large clusters (FS-L, XL, XXL) excel in magnetic hyperthermia experiments.
Collapse
Affiliation(s)
- P Bender
- Universidad de Cantabria, E-39005 Santander, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|