uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Simultaneous multiplexed detection of bacterial DNA sequences using the volume-amplified magnetic nanobead detection assay
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Genetics and Pathology.
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Solid State Physics.
Show others and affiliations
(English)Article in journal (Refereed) Submitted
National Category
Other Materials Engineering
Research subject
nano technology and functional materials
Identifiers
URN: urn:nbn:se:uu:diva-98022OAI: oai:DiVA.org:uu-98022DiVA: diva2:173179
Available from: 2009-02-13 Created: 2009-02-13 Last updated: 2009-02-16Bibliographically approved
In thesis
1. Molecular Diagnostics Using Volume-Amplified Magnetic Nanobeads: Towards the Development of a Novel Biosensor System
Open this publication in new window or tab >>Molecular Diagnostics Using Volume-Amplified Magnetic Nanobeads: Towards the Development of a Novel Biosensor System
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Micro- or nanometer sized magnetic particles (beads) currently have a vast range of life science applications in, for example, bioseparation techniques, cancer therapy, development of contrast agents and biosensing techniques. In the latter field, magnetic beads offer several unique advantages, including minimal background signals, physical and chemical stability and low manufacturing costs. Because of these properties, magnetic biosensing techniques are potential candidates for low-cost, easy-to-use molecular diagnostic devices.

This doctoral thesis focuses mainly on the proof of principle and further development of a new magnetic biosensor platform for detection of DNA targets, a potential candidate for a new generation of low-cost, easy-to-use diagnostic devices: the Volume-Amplified Magnetic Nanobead Detection Assay (VAM-NDA). The VAM-NDA principle combines target recognition by padlock probe ligation followed by rolling circle amplification (RCA) of the reacted probes with changes in Brownian relaxation behaviour of magnetic nanobeads (typically ~100 nm in diameter) induced by a change in hydrodynamic bead volume. More specifically, the RCA products (coils, typically ~1 μm in diameter) are detected magnetically by adding magnetic beads tagged with detection probes complementary to part of the repeating RCA-coil sequence. Thus, depending on the target concentration, a certain quantity of beads binds to the coils by base-pair hybridisation (bead immobilisation), resulting in a dramatic bead volume increase, which is then detected by measuring the complex magnetisation spectrum. Use of a commercial SQUID magnetometer for measuring complex magnetisation resulted in a detection limit in the low pM range for DNA targets with excellent quantification accuracy. Simultaneous multiplexing was also evaluated.

The stability and aging of typical commercial ferrofluids (suspensions of magnetic beads) were investigated by measuring the complex magnetisation of and interbead interactions in oligonucleotide-functionalised ferrofluids. In summary, the bead surface characteristics were found to have a strong impact on the measured dynamic magnetic properties.

Place, publisher, year, edition, pages
Uppsala: Universitetsbiblioteket, 2009. 102 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 598
Keyword
Magnetic Biosensors, Ferrofluid, Biofunctionalisation, Ferrofluidic Aging, Interbead Interactions, Magnetic Nanobeads, Complex Magnetisation, Brownian Relaxation, Padlock Probes, Rolling Circle Amplification
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:uu:diva-9542 (URN)978-91-554-7402-7 (ISBN)
Public defence
2009-03-06, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2009-02-13 Created: 2009-02-13 Last updated: 2009-06-22Bibliographically approved

Open Access in DiVA

No full text

By organisation
Nanotechnology and Functional MaterialsDepartment of Genetics and PathologySolid State Physics
Other Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 903 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf