Thesis Title

Development of Novel Collection and Biosensor Detection System for Microbial Organisms

Date of Graduation

Fall 2006


Master of Science in Biology



Committee Chair

Paul Durham


Detection of potentially harmful biological organisms has become increasingly important due to the threat of terrorist attacks, increased levels of black mold, and increased number of antibiotic resistant bacteria. Airborne dispersion of biological agents poses a serious medical threat that presents unique challenges for collection and detection. The goal of my project was to design and test the feasibility of novel method for collecting, concentrating, and identifying airborne biological organisms. To capture airborne microorganisms in an aqueous solution, a newly devised air collection system known as Aerosol Engineering for Retaining and Concentrating Airborne Organisms or AERCAO was utilized. This method in combination with centrifugation concentrated the samples almost 1000-fold. The samples were subjected to sonication to lyse the organisms and shear the genomic DNA in preparation for detection by a DNA biosensor. Initially, the specificity of the DNA probes was determined using polymerase chain reaction and gel electrophoresis. Probes shown to be selective for a particular bacteria or fungi were bound to gold electrodes. Hybridization of genomic DNA with a specific probe was monitored by changes in impedance. The results demonstrated that impedance increased following hybridization when compared to probe alone or follow incubation with unmatched DNA. Thus, my data validates the use of this methodology to collect, concentrate, and specifically detect a particular airborne microorganism.


nucleic acid biosensor, air collection, DNA, hybridization, impedance

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