Date of Award
9-6-2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Tatiana Esipova
Abstract
Our research focuses on advancing light-emitting organic molecules for applications in photocatalysis and biological sensing. This dissertation discusses the design, synthesis, and photophysical characteristics of these molecules. It explores their efficacy in photocatalytic processes and demonstrates the creation of fluorescent glutamate and pH sensors based on these compounds. Photocatalysis relies on electron or energy transfer between photoexcited catalysts and substrates. Commonly used photocatalysts like ruthenium or iridium complexes, although effective, suffer from high cost, laborious synthesis, and production of heavy-atom waste. To address this, we developed a series of heavy atom-free photocatalysts. Our approach centers around organic molecules composed of two covalently linked chromophores—referred to as donor-acceptor (D-A) dyads. Earlier, it was demonstrated that locking these dyads in orthogonal configuration enables formation of long-lived triplet excited states, vital for efficient photocatalysis. We demonstrated that these (D-A) type catalysts can efficiently catalyze UV- and visible-light-driven Atom Transfer Radical Addition (ATRA) reactions. We further synthesized a library of photocatalysts with absorption in the near infrared region (NIR) and studied their photophysical properties. Our goal was to establish a structure-function relationship, particularly triplet state quantum yield (ΦT) and evaluate catalytic efficiency across various reactions. There is an increased demand for developing fluorescent sensors emitting in the NIR. The exceptional photophysical characteristics of one of the (D-A) dyads synthesized, such as high quantum yield, made it suitable for creating fluorescent sensors. We exemplified this possibility by constructing a pH sensor which operates through the Photoinduced Electron Transfer (PeT) mechanism. We discussed the synthesis, impact of the sensor design on electron transfer, and further develop water-soluble compounds. Furthermore, we explain our approach and synthetic efforts in creating an optical glutamate sensor, where the recognition unit comprises a bacterial periplasmic binding protein (PBP) and small molecular dyes serving as fluorescent reporters.
Recommended Citation
Abuhadba, Sara, "Development of Dyes for Photocatalysis and Biological Sensing" (2024). Dissertations. 4116.
https://ecommons.luc.edu/luc_diss/4116
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
