Fine-tuning of magnetic and microfluidic viscous forces for specific magnetic bead-based immunocomplex formation

We investigate the working principle of a novel type of microfluidic sandwich immunoassay, as used for the detection of biomarkers. The heterogeneous assay is based on the specific interactions between an array of functionalized superparamagnetic beads and a flow of secondary superparamagnetic beads that carry the antigens and are simultaneously used as detection labels. We identify the main forces governing the immunoassay performance and develop a combined finite element method/analytical model to predict and control these forces. The clue for the improved assay specificity is in the fine-tuning of inter-bead magnetic dipolar and microfluidic viscous forces, which allows strongly reducing non-specific interactions, while enhancing the specific formation of immunocomplexes. We exploit our theoretical model to explain the enhanced sensitivity of magnetic bead-based immunoassay experiments performed in microfluidic chips. (C) 2013 AIP Publishing LLC.

Published in:
Journal of Applied Physics, 114, 064903
Melville, American Institute of Physics

 Record created 2013-09-19, last modified 2019-12-05

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