dc.contributor.author	Wang, Yunmiao	en
dc.contributor.committeechair	Wang, Anbo	en
dc.contributor.committeemember	Cooper, Kristie L.	en
dc.contributor.committeemember	Xu, Yong	en
dc.contributor.department	Electrical and Computer Engineering	en
dc.date.accessioned	2014-03-14T20:37:14Z	en
dc.date.adate	2011-06-27	en
dc.date.available	2014-03-14T20:37:14Z	en
dc.date.issued	2011-05-03	en
dc.date.rdate	2011-06-27	en
dc.date.sdate	2011-05-16	en
dc.description.abstract	DNA detection technology has developed rapidly due to its extensive application in clinical diagnostics, bioengineering, environmental monitoring, and food science areas. Currently developed methods such as surface Plasmon resonance (SPR) methods, fluorescent dye labeled methods and electrochemical methods, usually have the problems of bulky size, high equipment cost and time-consuming algorithms, so limiting their application for in vivo detection. In this work, an intrinsic Fabry-Perot interferometric (IFPI) based DNA sensor is presented with the intrinsic advantages of small size, low cost and corrosion-tolerance. This sensor has experimentally demonstrated its high sensitivity and selectivity. In theory, DNA detection is realized by interrogating the sensor's optical cavity length variation resulting from hybridization event. First, a microgap structure based IFPI sensor is fabricated with simple etching and splicing technology. Subsequently, considering the sugar phosphate backbone of DNA, layer-by-layer electrostatic self-assembly technique is adopted to attach the single strand capture DNA to the sensor endface. When the target DNA strand binds to the single-stranded DNA successfully, the optical cavity length of sensor will be increased. Finally, by demodulating the sensor spectrum, DNA hybridization event can be judged qualitatively. This sensor can realize DNA detection without attached label, which save the experiment expense and time. Also the hybridization detection is finished within a few minutes. This quick response feature makes it more attractive in diagnose application. Since the sensitivity and specificity are the most widely used statistics to describe a diagnostic test, so these characteristics are used to evaluate this biosensor. Experimental results demonstrate that this sensor has a sensitivity of 6nmol/ml and can identify a 2 bp mismatch. Since this sensor is optical fiber based, it has robust structure and small size ( 125μm ). If extra etching process is applied to the sensor, the size can be further reduced. This promises the sensor potential application of in-cell detection. Further investigation can be focused on the nanofabrication of this DNA sensor, and this is very meaningful topic not only for diagnostic test but also in many other applications such as food industry, environment monitoring.	en
dc.description.degree	Master of Science	en
dc.identifier.other	etd-05162011-135450	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-05162011-135450/	en
dc.identifier.uri	http://hdl.handle.net/10919/32875	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	Wang_Yunmiao_2011_f4.pdf	en
dc.relation.haspart	Wang_Yunmiao_2011_f2.pdf	en
dc.relation.haspart	Wang_Yunmiao_2011_f1.pdf	en
dc.relation.haspart	Wang_Yunmiao_2011_f3.pdf	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	Fiber Optic Biosensor	en
dc.subject	DNA Sequence Identification	en
dc.subject	Fabry-Perot Interferometer	en
dc.subject	Microprobe	en
dc.title	Microgap Structured Optical Sensor for Fast Label-free DNA Detection	en
dc.type	Thesis	en
thesis.degree.discipline	Electrical Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	masters	en
thesis.degree.name	Master of Science	en

Microgap Structured Optical Sensor for Fast Label-free DNA Detection

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