scholarly journals Formation of Visible Aggregates between Rolling Circle Amplification Products and Magnetic Nanoparticles as a Strategy for Point-of-Care Diagnostics

ACS Omega ◽  
2021 ◽  
Author(s):  
Darío Sánchez Martín ◽  
Reinier Oropesa-Nuñez ◽  
Teresa Zardán Gómez de la Torre
Keyword(s):  
Magnetic Nanoparticles ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Rolling Circle ◽  
Point Of Care Diagnostics

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

Polyelectrolyte-Coated Gold Magnetic Nanoparticles for Immunoassay Development: Toward Point of Care Diagnostics for Syphilis Screening

2013 ◽  
Vol 85 (14) ◽  
pp. 6688-6695 ◽  
Author(s):  
Dong Yang ◽  
Jianzhong Ma ◽  
Qinlu Zhang ◽  
Ningning Li ◽  
Jiangcun Yang ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Point Of Care ◽  
Point Of Care Diagnostics ◽  
Syphilis Screening

Multi-Channel Immunoassay System with Electrochemical Detection Toward Point-of-Care Diagnostics Using Magnetic Nanoparticles

2020 ◽  
Vol MA2020-01 (27) ◽  
pp. 1925-1925
Author(s):  
Sunga Song ◽  
Young Joo Kim ◽  
Hye-Lim Kang ◽  
Sumi Yoon ◽  
Dong-ki Hong ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Electrochemical Detection ◽  
Point Of Care ◽  
Point Of Care Diagnostics

scholarly journals Illumina and Nanopore methods for whole genome sequencing of hepatitis B virus (HBV)

2018 ◽  
Author(s):  
Anna L McNaughton ◽  
Hannah E Roberts ◽  
David Bonsall ◽  
Mariateresa de Cesare ◽  
Jolynne Mokaya ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Large Scale ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Genome Structure ◽  
Whole Genome ◽  
Nanopore Sequencing ◽  
Rolling Circle ◽  
B Virus

AbstractAdvancing interventions to tackle the huge global burden of hepatitis B virus (HBV) infection depends on improved insights into virus epidemiology, transmission, within-host diversity, drug resistance and pathogenesis, all of which can be facilitated by the large-scale generation of full-length virus genome data. Here we describe advances to a protocol to exploit the circular HBV genome structure, using isothermal rolling-circle amplification to enrich for HBV DNA and to generate concatemeric amplicons containing multiple successive copies of the same genome. We show that this product is suitable for Nanopore sequencing as single reads, as well as for generating short-read Illumina sequences. Nanopore reads can be used to implement a straightforward method for error correction that reduces the per-read error rate, by comparing multiple genome copies combined into a single concatemer and by comparing reads generated from plus and minus strands. Thus we can achieve improved consensus sequencing accuracy of 99.7% and resolve intra-sample sequence variants to form whole-genome haplotypes. The combination of isothermal amplification and Nanopore sequencing offers the longer-term potential to develop point-of-care tests for HBV, which could also be adapted for other viruses.

scholarly journals Characterization of Binding of Magnetic Nanoparticles to Rolling Circle Amplification Products by Turn-On Magnetic Assay

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 109 ◽  
Author(s):  
Sobhan Sepehri ◽  
Björn Agnarsson ◽  
Teresa Zardán Gómez de la Torre ◽  
Justin F. Schneiderman ◽  
Jakob Blomgren ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Specific Binding ◽  
Ac Susceptibility ◽  
Rolling Circle Amplification ◽  
Rolling Circle ◽  
Low Concentrations ◽  
Assay Performance ◽  
Particle Ensemble ◽  
Kinetics Of

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.

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