Backscattering particle immunoassays in wire-guide droplet manipulations

Jeong-Yeol Yoon, David J. You

Research output: Chapter in Book/Report/Conference proceedingChapter

20 Scopus citations


A simpler way for manipulating droplets on a flat surface was demonstrated, eliminating the complications in the existing methods of open-surface digital microfluidics. Programmed and motorized movements of 10 μL droplets were demonstrated using stepper motors and microcontrollers, including merging, complicated movement along the programmed path, and rapid mixing. Latex immunoagglutination assays for mouse immunoglobulin G, bovine viral diarrhea virus and Escherichia coli were demonstrated by merging two droplets on a superhydrophobic surface (contact angle = 155 ± 2°) and using subsequent back light scattering detection, with detection limits of 50 pg mL-1, 2.5 TCID50 mL-1 and 85 CFU mL-1, respectively, all significantly lower than the other immunoassay demonstrations in conventional microfluidics (∼1 ng mL-1 for proteins, ∼100 TCID50 mL-1 for viruses and ∼100 CFU mL-1 for bacteria). Advantages of this system over conventional microfluidics or microwell plate assays include: (1) minimized biofouling and repeated use (>100 times) of a platform; (2) possibility of nanoliter droplet manipulation; (3) reprogrammability with a computer or a game pad interface.

Original languageEnglish (US)
Title of host publicationJournal of Biological Engineering
Publication statusPublished - Nov 17 2008


ASJC Scopus subject areas

  • Biomedical Engineering
  • Environmental Engineering
  • Cell Biology
  • Molecular Biology

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