A microfluidic filter biochip-based chemiluminescence biosensing method for detection of Escherichia coli O157:H7

Varshney M., Li Y., Srinivasan B., Tung S., Erf G.F., Slavik M.F., Ying Y., Fang W.
Department of Biological and Agricultural Engineering, Center of Excellence for Poultry Science, Fayetteville, AR, United States; Department of Mechanical Engineering, Fayetteville, AR, United States; Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States; College of Biosystems Engineering and Food Science, Hangzhou, China; College of Animal Science and Technology, Zhejiang University, Hangzhou, China; 230 Engineering Hall, University of Arkansas, Fayetteville, AR 72701, United States

Abstract: A chemiluminescence biosensing method combined with a microfluidic filter biochip was investigated and evaluated for rapid and sensitive detection of Escherichia coli O157:H7, A microfluidic filter biochip was designed based on stepped filter configuration to concentrate and form a single layer of immunomagnetic microbeads inside a reaction microchamber. The filter biochip was assembled by thermally bonding two glass chips (microchamber and microchannel chips) together. The microchamber chip with one inlet and a reaction microchamber was 1 mm x 7 mm x 11.5 mu;m, and the microchannel chip with three outlets was 1 mm x 1 mm x 2.5 μm. Carboxyl-modified magnetic microbeads (8.27 μm diameter) covalently coupled with anti-E. coli O157:H7 antibodies were used for the separation of target bacteria from the background. The food sample containing E. coli O157:H7 was mixed with immunomagnetic microbeads and horseradish peroxidase-labeled anti-E. coli O157:H7 antibodies to form sandwich complexes. A syringe pump was used to inject the sandwich complexes into the filter biochip, and then luminol was added to generate a chemiluminescence signal, which was collected, measured, and recorded in real time through a fiber optic light guide connected to a photon detector coupled to a PC with a data acquisition unit. The results indicated that this filter biochip-based chemiluminescence biosensing method could detect as few as 71 cells of E. coli O157:H7 inside the reaction microchamber of 12 nL volume by single-batch sampling without pre-enrichment. The volume of sample used for testing was 100 μL. A multi-batch sampling technique was used to increase the capture efficiency of the immunomagnetic microbeads for detecting low numbers of E. coli O157:H7, which reduced the detection limit to 34 cells of E. coli O157:H7. The total detection time was 90 min. © 2006 American Society of Agricultural and Biological Engineers.
Author Keywords: Bacterial detection; Chemiluminescence; E. coli O157:H7; Microbeads; Microchannel; Microfluidic; Sampling technique

Year: 2006
Source title: Transactions of the ASABE
Volume: 49
Issue: 6
Page : 2061-2068
Cited by: 1
Link: Scorpus Link
Document Type: Article
Source: Scopus
 Authors with affiliations:
  1. Varshney, M., Department of Biological and Agricultural Engineering, Center of Excellence for Poultry Science, Fayetteville, AR, United States
  2. Li, Y., Department of Biological and Agricultural Engineering, Center of Excellence for Poultry Science, Fayetteville, AR, United States, 230 Engineering Hall, University of Arkansas, Fayetteville, AR 72701, United States
  3. Srinivasan, B., Department of Mechanical Engineering, Fayetteville, AR, United States
  4. Tung, S., Department of Mechanical Engineering, Fayetteville, AR, United States
  5. Erf, G.F., Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
  6. Slavik, M.F., Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
  7. Ying, Y., College of Biosystems Engineering and Food Science, Hangzhou, China
  8. Fang, W., College of Animal Science and Technology, Zhejiang University, Hangzhou, China
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