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Topic

An Optimized Approach for Photodynamic Inactivation (PDI) and other Singlet Oxygen Applications

Department of Chemistry

Date & location

• Thursday, October 30, 2025
• 9:00 A.M.
• Elliott Building, Room 230

Examining Committee

Supervisory Committee

• Dr. Heather Buckley, Department of Chemistry, ӣ��Ӱ�� (Supervisor)
• Dr. Jeremy Wulff, Department of Chemistry, UVic (Member)
• Dr. Stephanie Willerth, Department of Mechanical Engineering, UVic (Outside Member)

External Examiner

• Dr. Stefania Impellizzeri, Department of Chemistry and Biology, Toronto Metropolitan University

Chair of Oral Examination

• Dr. Justin Albert, Department of Physics and Astronomy, UVic

Abstract

Chapter 1 introduces the relevant background information for the basis of the project, including fundamentals on photodynamic inactivation (PDI), photosensitization and photosensitizers, singlet oxygen (¹O₂), and diazirines. The overall description of the project is provided and how it aims to diminish the knowledge gap.

Chapter 2 provides the proof-of-concept material for this thesis, where a porphyrin is covalently tethered to polyethylene terephthalate (PET) from thermal activation of diazirines. The material is then assessed for its ¹O₂ production in conjunction with its antimicrobial efficacy, which was a 1.76 log-reduction of Staphylococcus aureus.

Chapter 3 optimizes the light dose and porphyrin loading onto the surface by exploring how ¹O₂ production was affected by varying the amounts. With the optimized material in hand, it is then assessed for its durability to photobleaching under different light intensities, high (35,000 lx) and ambient (450 lx), for up to two weeks. The results indicate there was only a loss of ¹O₂ production after 1 week of high intensity exposure.

Chapter 4 provides the synthesis of other porphyrinoid molecules, including corroles, to explore how structure impacts ¹O₂ generation. The molecules’ ¹O₂ quantum yield is determined via direct detection methodology. Two of the porphyrins, with the highest quantum yields, are then tested using the solid-state methodology developed in Chapter 2.

Chapter 5 provides a summary of each chapter and subsequently explores potential future directions for the results from this work.