Thesis
Validation, optimization, and miniaturization of a dual ionophore ion selective electrode biosensor
Washington State University
Master of Science (MS), Washington State University
2019
Handle:
https://hdl.handle.net/2376/100712
Abstract
There is a critical need for rapid, sensitive biosensors which allow point-of-care detection and diagnosis of quickly progressing medical conditions such as septic infections. Presented herein are experiments related to the validation, optimization and miniaturization of a novel potentiometric biosensor based on ion selective membranes that could fill the current gap in available technology for pathogen detection. The dual ionophore ion selective electrode (di-ISE) circumvents measurement limitations occurring with traditional single membrane ion selective electrode biosensors by the inclusion of two separated but electrically connected membranes, each selective for a different ion. Characterization results show that the di-ISE behaves similarly to traditional electrodes when calibrated with electrolyte solutions, and proof-of-concept studies show that surface coverage with an inert material on one of the two membranes strongly influences the response characteristics. A fractional factorial optimization study is presented which shows that ion carrier concentrations in both of the membranes significantly affect the overall potential response when protein coverage on one of the membranes is simulated and that the optimal response occurs when ion carrier concentrations are kept at values above 0.5 wt%. Finally, di-ISE membranes are miniaturized to the micron scale to allow higher sensitivity to surface coverage. However, when functionalized with bioreceptor molecules, both traditionally sized and micro-membranes show limited response to protein capture due to low capture density, supporting the conclusion that more effective membrane functionalization methods are required to improve the response characteristics of the di-ISE biosensor. Though not effective for protein or cell detection in its current state, proof-of-concept studies with inert materials clearly show the potential for the di-ISE to be used as a rapid biosensor upon further modification.
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Details
- Title
- Validation, optimization, and miniaturization of a dual ionophore ion selective electrode biosensor
- Creators
- Olivia May Reynolds
- Contributors
- Bernard J. Van Wie (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525299801842
- Language
- English
- Resource Type
- Thesis