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Use of piezoelectric-excited millimeter-sized cantilever (PEMC) sensors for DNA-Based detection of pathogens and disease conditions
Please use this identifier to cite or link to this item:
http://hdl.handle.net/1860/3468
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| Title: | Use of piezoelectric-excited millimeter-sized cantilever (PEMC) sensors for DNA-Based detection of pathogens and disease conditions |
| Authors: | Rijal, Kishan |
| Keywords: | Chemical Engineering
Biosensors
Piezoelectric devices |
| Issue Date: | 15-Apr-2011 |
| 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 noncomplementary
DNA 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. |
| URI: | http://hdl.handle.net/1860/3468 |
| Appears in Collections: | Drexel Theses and Dissertations
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