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Development of a QCM-D based biosensor for detection of waterborne E. coli O157:H7

The contamination of drinking water by microbial pathogens is recognized as one of the most pressing water supply problems of our day. To minimize the impact of pathogens and parasites on the environment and public health, accurate methods are needed to evaluate their presence and concentration. Although various techniques exist to detect certain pathogens in water (e.g., immunofluorescence or PCR techniques), these are time- and labor-intensive. A direct, real-time method for detection and quantification of target organisms would thus be very useful for rapid diagnosis of water safety. A quartz crystal microbalance with dissipation monitoring (QCM-D) based biosensor for detection of waterborne pathogens (i.e., Escherichia coli O157:H7) was developed. The detection platform is based on the immobilization of affinity purified antibodies onto gold coated QCM-D quartz crystals via a cysteamine self-assembled monolayer. The results show that the optimal sensor response is the initial slope of the dissipation shift. A highly log-log linear response is obtained for detection of E. coli O157:H7 over a broad range of cell concentration from 3 x 105 to 1 x 109 cells/mL. The prepared biosensor also exhibits a log-log linear working range from 107 to 109 cells/mL for E. coli K12 D21, a non-pathogenic model organism. The biosensor also shows satisfactory selectivity using Bacillus subtilis . To our knowledge, this is the first study demonstrating the use of the slope of the dissipation shift as a sensor response when using QCM-D technology. / Keywords: Biosensor, QCM-D, E. coli O157:H7, polyc1onal antibodies, dissipation slope, cysteamine, self-assembled monolayer

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.116023
Date January 2008
CreatorsPoitras, Charles.
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Engineering (Department of Chemical Engineering.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 002839733, proquestno: AAIMR66959, Theses scanned by UMI/ProQuest.

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