Thesis
Enhancing the longevity of ion-selective electrode arrays in bioreactors
Washington State University
Master of Science (MS), Washington State University
2007
Handle:
https://hdl.handle.net/2376/101823
Abstract
It has been observed that Ion-Selective Electrodes (ISEs) suffer performance loss after long time use in bioreactors. It is speculated that protein adsorption inactivates ISEs by inhibiting ion permeation. The amphiphilic polymer, poly(2-methacryloyloxyethylphosphorylcholine-co-butyl methacrylate) or poly(MPC-co-BMA), was coated on ISEs to improve their longevity when exposed to bioreactor effluent for long time periods. It was hypothesized that the polymer coating would prevent protein adsorption by forming a hydrogel on the ISE surface, rendering the protein adsorption process reversible. In this project, K+ ISEs made with valinomycin as the ionophore were used to determinate the effects of the polymer coating on response slopes, limits of detection (LODs), interference with NH4+, and longevity in batch bioreactor effluent, by coating the ISEs with five different polymer solutions: 0%, 0.01%, 0.10%, 1.0%, and 10% by weight. The results showed that the polymer coated ISEs maintained a Nernstian response through long time exposure to bioreactor effluent as expected. However, the polymer coating tended to simultaneously reduce the ISE LOD, with a negative correlation between the weight percent of polymer and the LOD. The polymer coating tended to increase ISE interference from NH4+. This implies that the reduction of the ISE LOD is not severe enough to negatively affect ISE performance in most bioreactor applications because of the relatively high K+ content in the growth media. Therefore, the results validate the use of poly(MPC-co-BMA) to coat ISEs and render them suitable for applications involving biological fluids.
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Details
- Title
- Enhancing the longevity of ion-selective electrode arrays in bioreactors
- Creators
- Hajime Fuchida
- 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
- 99900525287701842
- Language
- English
- Resource Type
- Thesis