A STUDY OF BIOSENSORS: NOVEL APPLICATION AND NOVEL ELECTRODE

Amperometric biosensing technology received increasing attention in the medical field. This dissertation was divided into two parts: novel application for Ir-C sensor, specifically the detection of a biomarker for metastasis of prostate cancer; and novel electrode materials for enhancing sensing performance particularly the bi-metallic nano-catalyst Pt-Ru.Part IProstate-specific antigen (PSA) test was commonly used in clinical practice to screen and diagnose prostate cancer. Weaknesses of this approach included a lack of specificity and the inability to distinguish between aggressive and indolent cancers. A promising prostate cancer biomarker, alpha-methylacyl-CoA racemase (AMACR), had been previously demonstrated to distinguish cancer from healthy and benign prostate cells with high sensitivity and specificity. However, no accurate clinically useful assay has been developed. Therefore, the development of a single use, disposable biosensor for AMACR detection was reported in Part I of this dissertation. Human blood samples were used to verify its validity, reproducibility and reliability. The average AMACR levels in the prostate cancer patients were 10-fold higher than either the controls or HGPIN patients. We were able to achieve 100% accuracy in separating prostate cancer patients from controls. Our results provided strong evidence demonstrating that this biosensor can perform a reliable assay for prostate cancer detection and diagnosis.Part II Platinum is generally an excellent catalyst, however, it is known to reduce in its catalytic performance due to poisoning. In order to overcome this shortcoming, a second metal such as ruthenium is mixed with Pt forming a bi-metallic material for electrochemical oxidation/reduction. Ru requires less activation energy than Pt to absorb OHabs and Oads, common poison species. Consequently, Pt-Ru bi-metallic electrode material outperformed pure Pt and Ru electrodes. In order to study the electrochemical performance of Pt-Ru electrodes, we compared the three electrode materials for their abilities to detect H2O2. At an applied electrochemical potential of +0.2 versus Ag/AgCl reference electrode, the sensitivities of Pt, Ru and Pt-Ru for detection of H2O2 oxidation were 76µA/mM, 15µA/mM and 118µA/mM respectively. Pt-Ru electrode had the best performance because the presence of a second metal such as Ru helped to minimize the poisoning of Pt active sites.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Lin, Po-Yuan

Contributors dc:contributor

• Liu, Chung-Chiun
• McGuffin-Cawley, James

• Materials Science
• Chemical Engineering
• Biomedical Engineering
• Prostate Cancer
• Biosensor
• Bi-metallic

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1363961554

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1363961554