Thesis Format
Monograph
Degree
Master of Science
Program
Chemistry
Supervisor
Zhifeng Ding
Abstract
Electrochemiluminescence (ECL) is the emission of light from excited molecules generated by electron transfer between radicals electrogenerated. Chemiluminescence (CL) is light emitted from chemical reactions between a luminor and coreactant. Four pyrene-based donor-acceptor complexes have been investigated to determine their redox potentials and the mechanisms of various ECL pathways using modern analytical methods: spooling ECL spectroscopy, ECL voltage curves, and photoluminescence (PL) spectroscopy. Their absolute quantum efficiencies (ΦECL) have been successfully determined in both annihilation and benzoyl peroxide (BPO) coreactant routes. A novel instrumentation strategy using a spectrometer and integrating sphere has been utilized for the first time to determine absolute CL efficiencies of luminol/hydrogen peroxide systems along with spectral evolution and devolution. CL properties of abundant chlorophyll has been investigated as well, along with its absolute quantum efficiency for the first time.
Summary for Lay Audience
Luminescence techniques, including electrochemiluminescence (ECL) and chemiluminescence (CL), are powerful analytical tools that generate light through chemical reactions. In ECL, electrochemically generated radical species react to form excited-state molecules, emitting light upon returning to their ground state. This technique offers advantages such as high sensitivity, accurate analyte detection, and minimal background interference. Our research explored the ECL properties of four newly synthesized pyrene-based donor-acceptor compounds. These materials, featuring electron-accepting pyridyl-borane groups and electron-donating triarylamine entities, were investigated using various spectroscopic and electrochemical methods. The study aimed to gain mechanistic insights into their light-emitting properties and assess their potential for applications in light-emitting devices and immunoassays. By combining ECL experiments with other analytical techniques, this work contributes to the fundamental understanding of excited-state formation processes, crucial for developing efficient ECL candidates and expanding their applications in biomedical research and clinical diagnostics.
CL involves the light emission from a molecular excited state accessed through energy released in a chemical reaction, is frequently used in biological analysis, imaging, and environmental monitoring due to its low background signal, high sensitivity, and rapidity. Various CL probes, such as organic compounds, or metal nanomaterials, have been developed. The most common CL reagent is luminol, often used with hydrogen peroxide (H2O2) as a coreactant. Different CL systems have various reaction mechanisms, necessitating a general model to investigate the influence of reactant structures and conditions. In our lab, we delve into the chemical dynamics of CL reactions using spectroscopy measurements. We aim to accurately quantify the absolute CL quantum efficiencies by calibrating our spectrometer system. This research also focuses on quantifying the CL quantum efficiency of chlorophyll compounds to uncover insights into their luminescent properties and reaction efficiencies.
Recommended Citation
Jahanghiri, Sara, "Advancing Luminescent Technologies: Novel Electrochemiluminescence and Chemiluminescence Studies for Analytical Applications" (2024). Electronic Thesis and Dissertation Repository. 10315.
https://ir.lib.uwo.ca/etd/10315