Photochemical Sciences Ph.D. Dissertations


Raman Spectroscopic Imaging Analysis of Signaling Proteins and Protein Cofactors in Living Cells

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Photochemical Sciences

First Advisor

H. Peter Lu (Advisor)

Second Advisor

John Cable (Committee Member)

Third Advisor

Alexey Zayak (Committee Member)

Fourth Advisor

Anita Simic (Other)


Proteins play a central role in biological processes. Broad classes of protein types are involved in the innumerable functions of living systems, such as catalysis of the biochemical reactions, transportation of the essential molecules, defense of the immune system, and the transmission of messages from cells to cells. In our projects, we have combined the analytical approaches including surface-enhanced Raman scattering (SERS), fluorescence microscopy, electrochemistry, and computational methods to investigate the structures and functions of the proteins and signaling molecules in the living cells. In our research, we have studied the interactions and functions of dopamine transporters (DAT), dopamine receptors (DARs), and several signaling molecules such as dopamine (DA), amphetamine (AMP), methamphetamine (MAMP), and methylenedioxypyrovalerone (MDPV) in living cells. The interactions between signaling molecules and DAT or DARs are crucial for the functioning of dopaminergic pathways. In our project, we have probed interactions of signaling proteins including DAT and DARs and investigated the changes that happen in signaling proteins, other interacting compounds or intracellular contents of the second messenger such as cyclic adenosine monophosphate (cAMP). The second messenger like cAMP is important in many biological processes which are produced due to interactions of the signaling protein in living cells. Our studies on DA-DAT or DA-DARs interactions mainly utilize the Raman spectroscopy to characterize the selectivity and efficacy of psychopharmaceutic drugs. In addition, we have also studied the redox states and mechanism of protein cofactors in different experimental conditions. We have probed and characterized the redox states and mechanisms of FMN cofactors in biological and non-biological environments using electrochemistry, SERS measurements, and computational measurements. The results obtained from our research could be useful in the diagnosis of abnormalities or diseases originated from malfunctioning of proteins or protein-ligand interactions.