Sensitive and rapid detection of cholera toxin subunit B using magnetic frequency mixing detection

Achtsnicht, Stefan; Neuendorf, Christian Simon; Faßbender, Tobias; Nölke, Greta; Offenhäusser, Andreas; Krause, Hans‐Joachim; Schröper, Florian

doi:10.1371/journal.pone.0219356

Cited by 24 publications

(27 citation statements)

References 48 publications

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“…Based on results achieved with enzyme-based colorimetric immunofiltration columns (ABICAP ® , Senova Gesellschaft für Biowissenschaft und Technik mbH, Weimar, Germany), Achtsnicht et al [ 150 ] established a magnetic sandwich immunoassay inside a 3D immunofiltration column. Therefore, monoclonal capture antibodies specific for cholera toxin B subunit were immobilized on polyethylene matrix of the filtration column, whereas monoclonal detection antibodies were conjugated to superparamagnetic beads.…”

Section: Portable Immunoassay Techniques With Multiplexing Capabilmentioning

confidence: 99%

Multiplex Immunoassay Techniques for On-Site Detection of Security Sensitive Toxins

Pöhlmann

Elßner

2020

Toxins

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Biological toxins are a heterogeneous group of high molecular as well as low molecular weight toxins produced by living organisms. Due to their physical and logistical properties, biological toxins are very attractive to terrorists for use in acts of bioterrorism. Therefore, among the group of biological toxins, several are categorized as security relevant, e.g., botulinum neurotoxins, staphylococcal enterotoxins, abrin, ricin or saxitoxin. Additionally, several security sensitive toxins also play a major role in natural food poisoning outbreaks. For a prompt response to a potential bioterrorist attack using biological toxins, first responders need reliable, easy-to-use and highly sensitive methodologies for on-site detection of the causative agent. Therefore, the aim of this review is to present on-site immunoassay platforms for multiplex detection of biological toxins. Furthermore, we introduce several commercially available detection technologies specialized for mobile or on-site identification of security sensitive toxins.

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Section: Portable Immunoassay Techniques With Multiplexing Capabilmentioning

confidence: 99%

Multiplex Immunoassay Techniques for On-Site Detection of Security Sensitive Toxins

Pöhlmann

Elßner

2020

Toxins

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“…Their signal can usually be picked up using a receive coil; however, other magnetic detectors can also be employed [ 6 ]. Due to its high sensitivity, FMMD has been successfully applied to realize magnetic immunoassays for the detection of a multitude of different analytes, for instance, viruses [ 7 ], antibiotics [ 8 ], or bacterial toxins [ 9 ]. Furthermore, FMMD enables the distinction of different types of MNP based on their different frequency mixing response spectrum [ 10 , 11 , 12 ], which opens the potential for multi-analyte detection.…”

Section: Introductionmentioning

confidence: 99%

Comparative Modeling of Frequency Mixing Measurements of Magnetic Nanoparticles Using Micromagnetic Simulations and Langevin Theory

et al. 2021

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Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90% of the frequency mixing magnetic response signal is generated by the largest 10% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory.

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“…Afterward, secondary antibodies specifically binding to the previously enriched antibodies are applied, and subsequently specially functionalized magnetic particles (MNPs) are added, labelling the secondary antibodies. After a washing step to elute unbound MNPs, IFSc are simply inserted into the detection head of a portable magnetic read-out device in which retained MNPs are then detected by means of frequency magnetic mixing detection technology (FMMD), using a low-and a highfrequency magnetic excitation field [10][11][12][13][14][15][16][17]. An alternately oscillating positive and negative magnetic saturation of MNPs with a frequency of 2•f2 of 122 Hz is obtained when exposing the particle to a low (which was not certified by peer review) is the author/funder.…”

Section: Introductionmentioning

confidence: 99%

Brief Communication: Magnetic Immuno-Detection of SARS-CoV-2 specific Antibodies

Pietschmann

Vöpel

Spiegel

et al. 2020

Preprint

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10SARS-CoV-2 causes ongoing infections worldwide, and identifying people with immunity is 11 becoming increasingly important. Available point-of-care diagnostic systems as lateral flow assays 12 have high potential for fast and easy on-site antibody testing but are lacking specificity, sensitivity 13 or possibility for quantitative measurements. Here, a new point-of-care approach for SARS-CoV-2 14 specific antibody detection in human serum based on magnetic immuno-detection is described and 15 compared to standard ELISA. For magnetic immuno-detection, immunofiltration columns were 16 coated with a SARS-CoV-2 spike protein peptide. SARS-CoV-2 peptide reactive antibodies, spiked 17 at different concentrations into PBS and human serum, were rinsed through immunofiltration 18 columns. Specific antibodies were retained within the IFC and labelled with an isotype specific 19 biotinylated antibody. Streptavidin-functionalized magnetic nanoparticles were applied to label the 20 secondary antibodies. Enriched magnetic nanoparticles were then detected by means of frequency 21 magnetic mixing detection technology, using a portable magnetic read-out device. Measuring 22 signals corresponded to the amount of SARS-CoV-2 specific antibodies in the sample. Our 23 preliminary magnetic immuno-detection setup resulted in a higher sensitivity and broader 24 2 detection range and was four times faster than ELISA. Further optimizations could reduce assay 25 times to that of a typical lateral flow assay, enabling a fast and easy approach, well suited for point-26 of-care measurements without expensive lab equipment.

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Sensitive and rapid detection of cholera toxin subunit B using magnetic frequency mixing detection

Cited by 24 publications

References 48 publications

Multiplex Immunoassay Techniques for On-Site Detection of Security Sensitive Toxins

Multiplex Immunoassay Techniques for On-Site Detection of Security Sensitive Toxins

Comparative Modeling of Frequency Mixing Measurements of Magnetic Nanoparticles Using Micromagnetic Simulations and Langevin Theory

Brief Communication: Magnetic Immuno-Detection of SARS-CoV-2 specific Antibodies

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