Microfluidic device monitoring of waterborne pathogens in model water distribution systems

Jeong Yeol Yoon, Jin Hee Han, Christopher Y. Choi, Brian Heinze, Lonnie J. Lucas

Research output: Contribution to conferencePaperpeer-review

1 Scopus citations


Microfluidic device detections of E. coli K12 in deionized (Dl) water and E. coli in field water sample were demonstrated through static light scattering of latex immunoagglutination using proximity optical fibers. This method is a fully-automated, one-step detection, and requires neither sample pre-treatment nor cell culturing often required in many on-chip detections. We have used highly carboxylated polystyrene submicron latex particles without surfactants to enhance diffusional mixing and prevent non-specific bindings towards successful demonstration of latex immunoagglutination in microfluidic device. Detection of E. coll was performed by taking microscopic images from the view cell of a microfluidic device and counting the fractions of non-agglutinated and agglutinated particles. The limit of detection (LOD) was ca. 150 CFU ml -1 with this method for both E. coli K12 in Dl water and E. coli in field water sample, indicating no non-specific bindings. Improved LOD of ca. 5 CFU ml-1 was achieved by measuring forward static light scattering from microfluidic device, using proximity optical fibers and a USB-powered miniature spectrometer. The total assay time for sample preparation (mostly dilutions) and on-chip assay (mostly injections and short incubation time) was <10 min. Devices made out of polydimethylsiloxane (PDMS) were reusable up to 4 times, while those made out of polyethylene glycol (PEG) showed improved reusability of up to 20 times.

Original languageEnglish (US)
StatePublished - 2007
Event2007 ASABE Annual International Meeting, Technical Papers - Minneapolis, MN, United States
Duration: Jun 17 2007Jun 20 2007


Other2007 ASABE Annual International Meeting, Technical Papers
Country/TerritoryUnited States
CityMinneapolis, MN


  • E. coli
  • Lab-on-a-chip
  • Latex immunoagglutination
  • Light scattering
  • Microfluidic device
  • Microspheres
  • Optical fiber
  • Particle immunoassay

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Engineering(all)


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