Electrochemical detection of thiol containing molecules

Thesis

This thesis presents the experimental work with the main aim of developing new electrochemical based methods for detecting thiol-containing molecules, specifically homocysteine, glutathione, and cysteine, with little to no sample treatment in an aqueous system. The first chapter introduces the principles and techniques of electrochemistry. The second chapter gives a brief introduction to the importance of thiol containing molecules in biological systems; thus, the need for its analytical determination and quantification.

This thesis reports a suitable electrochemical methodology to selectively detect thiols using a combination of different ortho-quinone derived mediators and carbon electrode materials. The methodology exploits two ortho-quinone reaction pathways with a thiol molecule, electrocatalytic and 1,4-Michael addition reaction. Proof-of-concept was carried out in buffered systems then realized in synthetic and real biological sample; where ultimately, quantitative performance in 'real world' sample was shown to be analogous to a commercially available enzyme test.

Finally, screen-printed electrodes are employed in the presented study to show the prospect for a point-of-care system. The compact design, such as having a three-electrode system printed onto a single strip, allows versatility and easy utilization. These electrochemical chips are ideal and advantageous for high throughput applications.

Overall, the development of a quick, easy, and cheap methodology for thiol determination discussed in this thesis makes a significant contribution to the clinical and biomedical community as an alternative and simpler diagnostic pathway.

Authors: Lee, P

• DOI: 10.5287/ora-g2vgb1oxe
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford