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Dissertation
Use of piezoelectric-excited millimeter-sized cantilever (PEMC) sensors for DNA-based detection of pathogens and disease conditions
Doctor of Philosophy (Ph.D.), Drexel University
May 2007
DOI:
https://doi.org/10.17918/etd-3468
Abstract
In this study, Piezoelectric-Excited Millimeter-Sized Cantilever (PEMC) sensors were used to detect pathogens and disease conditions using DNA-based detection technique. Using Stx-2 gene as a unique identifier, the model pathogen E. coli O157:H7 was detected using a simplified and rapid genomic DNA extraction method (30 min) in both buffer and proteinous complex matrix at ~2,000 pathogens per mL. Single Nucleotide Polymorphism (SNP) of DNA of length 10 to 60 nt were detected via nucleic-acid hybridization at 1 femtomolar concentration. Synthetic single stranded DNA, 10 to 288 bases long were detected by hybridization. For the first time, Taq-polymerase based extension of captured DNA was performed on the cantilever sensor thus increasing hybridized mass by ~2.2 pg. The PEMC sensor showed high specificity in detecting complementary DNA in presence of 10,000 times higher concentration noncomplementaryDNA strands. Using antibody-antigen assay, E. coli O157:H7 was detected at 10 cells/mL and developed a protocol for regeneration of the sensor surface for multiple uses. Another significant result is the measurement of alkanethiol chemisorption on Au<111> coated sensor surface at 1 femtomolar. At higher alkanethiol concentrations the sensor responses were proportionately, but non-linearly, higher. However, the responses to C4, C8, C11, C16 and C18 alkanethiols at 1 mM were linearly proportional. We report for the first time that, once the Au-surface is equilibrated at 1 pM, further chemisorption at a lower concentration does not take place, even though over 99% of adsorption sites is vacant.
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Details
- Title
- Use of piezoelectric-excited millimeter-sized cantilever (PEMC) sensors for DNA-based detection of pathogens and disease conditions
- Creators
- Kishan Rijal - DU
- Contributors
- Rajakkannu Mutharasan (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- Chemical (and Biological) Engineering [Historical]; College of Engineering (1970-2026); Drexel University
- Other Identifier
- 3468; 991014632206204721