Thiede, Jan (2024). Supramolecular Self-Assembly of Pyrene-Modified Amphiphilic DNA Nanostructures. (Thesis). Universität Bern, Bern
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Abstract
In the first chapter, topics related to this thesis are introduced. Supramolecular polymers in aqueous medium, general aspects and structural features of deoxyribonucleic acid (DNA), the preparation of synthetic oligomers via solid-phase synthesis, nanostructures built by DNA, and light harvesting and energy transfer in supramolecular systems are introduced. In the second chapter, the aim of the thesis is described. The subsequent chapters describe the results, discussion, conclusion, and outlook of the experimental work. In the third chapter, the supramolecular self-assembly of amphiphilic 3’-end modified pyrene-DNA conjugates is described. Modifications of DNA with three pyrene isomers are compared, and their light-harvesting capabilities are explored. The supramolecular assembly of pyrene-DNA conjugates decorated with the three isomers yielded nanostructures with different morphologies. All assemblies exhibit light-harvesting properties. Interestingly, the 2,7-dialkynyl pyrene isomer exhibited a non-FRET energy transfer. In the fourth chapter, the supramolecular assembly of pyrene-DNA conjugates is further investigated. The influence of spermine and ethanol concentrations, as well as the impact of the number of pyrene modifications on the sticky ends, is examined. In the fifth chapter, the supramolecular assembly of the 3’-/5’-end modified pyrene-DNA conjugates paired with a complementary unmodified DNA strand is presented. Pyrene-DNA conjugates bearing sticky ends with one, two, and three 2,7-dialkynyl and 1,6-dialkynyl pyrene are compared. The morphologies of the nanostructures formed by the two isomers are similar. They assemble into single vesicles and aggregates of vesicles. Switching from three to two pyrene modifications in the sticky ends reduces the size of the formed nanostructures. In the sixth chapter, the supramolecular self-assembly of terminal functionalized 3’-/5’-end modified pyrene-DNA conjugates is described. This chapter describes the functionalizations of the pyrene-DNA conjugate with an alkyne, polyethylene glycol, or a branched N-acetyl galactosamine. Interestingly, these modifications influence the morphologies of the supramolecular assemblies only marginally. In the seventh chapter, the supramolecular assembly of highly modified phenanthrene-DNA conjugates is presented. The conjugates presented in this chapter contain phenanthrene modifications in the middle of the strand and at the 3’-ends form filled spherical nanostructures. A doping experiment with a pyrene-containing phenanthrene-DNA conjugate proved their light-harvesting capabilities. In the eighth chapter, overall conclusions are drawn, and future perspectives are outlined.
| Item Type: | Thesis |
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| Dissertation Type: | Cumulative |
| Date of Defense: | 5 April 2024 |
| Subjects: | 500 Science > 540 Chemistry 500 Science > 570 Life sciences; biology |
| Institute / Center: | 08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) |
| Depositing User: | Hammer Igor |
| Date Deposited: | 25 Nov 2024 07:35 |
| Last Modified: | 25 Nov 2024 10:39 |
| URI: | https://boristheses.unibe.ch/id/eprint/5645 |
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