Self-assembled magnetic bead chains for sensitivity enhancement of microfluidic electrochemical biosensor platforms
2015 (English)In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 15, no 22, 4314-4321 p.Article in journal (Refereed) Published
In this paper, we present a novel approach to enhance the sensitivity of microfluidic biosensor platforms with self-assembled magnetic bead chains. An adjustable, more than 5-fold sensitivity enhancement is achieved by introducing a magnetic field gradient along a microfluidic channel by means of a soft-magnetic lattice with a 350 mu m spacing. The alternating magnetic field induces the self-assembly of the magnetic beads in chains or clusters and thus improves the perfusion and active contact between the analyte and the beads. The soft-magnetic lattices can be applied independent of the channel geometry or chip material to any microfluidic biosensing platform. At the same time, the bead-based approach achieves chip reusability and shortened measurement times. The bead chain properties and the maximum flow velocity for bead retention were validated by optical microscopy in a glass capillary. The magnetic actuation system was successfully validated with a biotin-streptavidin model assay on a low-cost electrochemical microfluidic chip, fabricated by dry-film photoresist technology (DFR). Labelling with glucose oxidase (GOx) permits rapid electrochemical detection of enzymatically produced H2O2.
Place, publisher, year, edition, pages
2015. Vol. 15, no 22, 4314-4321 p.
Biochemistry and Molecular Biology Nano Technology
IdentifiersURN: urn:nbn:se:kth:diva-177980DOI: 10.1039/c5lc00796hISI: 000364072300008PubMedID: 26394820ScopusID: 2-s2.0-84946092223OAI: oai:DiVA.org:kth-177980DiVA: diva2:875916
QC 201512022015-12-022015-11-302015-12-02Bibliographically approved