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ERIC Number: ED526599
Record Type: Non-Journal
Publication Date: 2009
Pages: 296
Abstractor: As Provided
Reference Count: 0
ISBN: ISBN-978-1-1095-8431-8
Biological Mimics: A New Paradigm in the Detection of Toxic Compounds
Monty, Chelsea Nicole
ProQuest LLC, Ph.D. Dissertation, University of Illinois at Urbana-Champaign
The purpose of this thesis is to introduce a new idea: using biological mimics in the detection of toxic compounds. Biological mimics imitate the active site of a given enzyme or have catalytic chemistry similar to enzymes and can be used in place of biological molecules to provide longer stability and simpler operation. In the following text the development and testing of two types of biological mimic sensors will be described: (1) an acetylcholinesterase mimic sensor; and (2) a non-biological inhibition based sensor. First, an acetylcholinesterase-based enzyme biosensor was developed using a multi-phase microsensor platform. The biosensor sensor was sensitive to parts-per-trillion level of toxic phosphonates, specifically malathion. However, the acetylcholinesterase sensor was only stable for 9 days with refrigeration. For portable applications, a shelf-life of 9 days is unacceptable and refrigeration is a costly alternative. In order to increase stability, oxime molecules, an acetylcholinesterase mimic, were used to detect toxic acetylcholinesterase inhibitors in multi-phase microdevice. The oxime sensor also has parts-per-trillion level sensitivity and is selective only to acetylcholinesterase inhibitors with limited shelf-life issues. The first half of this thesis will describe the development, optimization, and testing of the oxime microsensor. The second part of the thesis will focus on a new technique in chemical detection: Non-biological Inhibition Based Sensing (NIBS). This method uses a new approach to chemical amplification, where the analyte inhibits rather than enhances the rate of a catalytic reaction. Although there are many possible catalysts for this technique, such as enzymes, this thesis focuses on using the selective binding found in colorimetric detection. Colorimetric methods are selective; however, they are not particularly sensitive. Using non-biological based molecules allows for selective detection without the shelf-life issues associated with enzymes. Two examples are presented in this work: detection of toxic sulfides and toxic arsines. The second half of the thesis will focus on development, optimization, and testing of the NIBS technique. The techniques reported in this thesis can be then be expanded to mimic other biological molecules and processes. Mimic sensors could be developed for other common toxicological modes, for example, oxidative stress and phosphorylation inhibitors. The ability to detect toxins using biological mimics allows for creation of toxicity assays with the selectivity of biomolecules and the stability of chemical compounds. Other mimic sensors can be developed using the NIBS detection scheme to create a library of sensitive, selective, and portable detectors for a variety of toxin. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page:]
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Publication Type: Dissertations/Theses - Doctoral Dissertations
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A