Analytical approaches to optimising organic semiconductor films for light-induced reactive oxygen species production
File(s)
Author(s)
Kaye, Joe
Type
Thesis
Abstract
Cancer and antimicrobial resistance are two of the leading threats to human health in the modern world.
Thus, new treatments and disinfection techniques must be developed to combat this current and rising
threat. One area of interest is using photosensitisers, which generate reactive oxygen species in light.
Reactive oxygen species react with the structure of cells indiscriminately and cause oxidative damage,
leading to cellular death. Photodynamic therapy offers the advantages of being selectively activated,
leading to targeted therapy. However, new analytical approaches are needed to provide data at a higher
throughput.
One potential photosensitiser is via the use of organic donor polymers and small acceptor molecules,
which absorb in visible light, such as F8T2 and O-IDTBR. These produce more reactive oxygen species
compared to baseline tests using a hydroethidine dye.
To expand upon the structures of interest, novel derivatives of F8T2, O-IDTBR and IDFBR were
explored using Time-Dependent Density Functional Theory. From the initial three compounds of
interest, 377 derivatives of interest were developed.
A high-throughput solution-based assay was developed, using HPLC technology to move away from
traditional surface testing. The assay offers advantages such as using less reagent, collecting more data
points in a shorter time frame and a reduction in potential variables. An agreement between the solid
phase and solution phase was found in F8T2/O-IDTBR systems, to allow for a faster, initial exploration
of reactive oxygen species generation of the blends.
Finally, F8T2’s efficacy against MCF-7 cancer cells was investigated. It was found that F8T2 under
light produced a cell-killing effect within an hour across several concentrations. The highest
concentration of F8T2 produced the greatest cell killing effect. Further work in the application of F8T2,
and other organic molecules/blends can be explored via testing efficacy on skin cancer cell lines and on
bacterial species.
Thus, new treatments and disinfection techniques must be developed to combat this current and rising
threat. One area of interest is using photosensitisers, which generate reactive oxygen species in light.
Reactive oxygen species react with the structure of cells indiscriminately and cause oxidative damage,
leading to cellular death. Photodynamic therapy offers the advantages of being selectively activated,
leading to targeted therapy. However, new analytical approaches are needed to provide data at a higher
throughput.
One potential photosensitiser is via the use of organic donor polymers and small acceptor molecules,
which absorb in visible light, such as F8T2 and O-IDTBR. These produce more reactive oxygen species
compared to baseline tests using a hydroethidine dye.
To expand upon the structures of interest, novel derivatives of F8T2, O-IDTBR and IDFBR were
explored using Time-Dependent Density Functional Theory. From the initial three compounds of
interest, 377 derivatives of interest were developed.
A high-throughput solution-based assay was developed, using HPLC technology to move away from
traditional surface testing. The assay offers advantages such as using less reagent, collecting more data
points in a shorter time frame and a reduction in potential variables. An agreement between the solid
phase and solution phase was found in F8T2/O-IDTBR systems, to allow for a faster, initial exploration
of reactive oxygen species generation of the blends.
Finally, F8T2’s efficacy against MCF-7 cancer cells was investigated. It was found that F8T2 under
light produced a cell-killing effect within an hour across several concentrations. The highest
concentration of F8T2 produced the greatest cell killing effect. Further work in the application of F8T2,
and other organic molecules/blends can be explored via testing efficacy on skin cancer cell lines and on
bacterial species.
Version
Open Access
Date Issued
2025-11-05
Date Awarded
2026-03-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Haque, Saif
Salehi-Reyhani, Ali
Sponsor
European Union
Publisher Department
Department of Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)