The use of a conductive polypyrrole urea biosensor for the detection of urea in blood plasma is investigated.Urease was incorporated into a polypyrrole film by galvanostatic polymerisation. The presence of urea was verified, and the activity of the enzyme in the polypyrrole film was confirmed. The inherent electroactive properties of the polypyrrole-urease film has enabled the production of a flow injection amperometric biosensor for the reliable determination of urea. Greater sensitivity and stability was achieved when a pulsed amperometric detection system was implemented. The analysis of urea in human blood plasma by potentiometry, amperometry and pulsed amperometry was achieved with the assistance of an anion exchange separation prior to the electrochemical detection of urea. A polypyrrole-sulfite oxidase film was developed for use in an amperometric biosensor for sulfite determination. The response of the biosensor to sulfate was linear from 0 to 80 mg/L and the minimum detectable amount was 5 mg/L. Useful interferants in sulfite determination such as ascorbic acid, sodium nitrate and sodium sulfate did not respond to the biosensor. The excellent reproducibility of the sulfite response provides the basis for the construction of a disposable or renewable biosensor for sulfite determination. The analysis of sulfite in wine and beer was accomplished and no pretreatment was required. / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:ADTP/189036 |
| Date | January 1994 |
| Creators | Shaw, Shannon Joanne, University of Western Sydney, Faculty of Science and Technology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
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