Date of Award
8-2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
Committee Chair/Advisor
Dr. Jason G McNeill
Committee Member
Dr. Dvora Perahia
Committee Member
Dr. Leah Casabianca
Committee Member
Dr. Brian N. Dominy
Committee Member
Dr. David Reid Jacobson
Abstract
Previous publications from our lab demonstrated viable approaches to design a photo-switching nanoparticle with arguably superior brightness and photostability resulting in an improved resolution in localization-based microscopy, as compared to other photo-switching dyes or particles. As a follow-up, this dissertation is focused on two major tasks: first, developing nanoparticles with better photo-switching properties for super-resolution imaging; second, trying to achieve a better physical picture of the mechanisms involved in photo-switching, including polaron dynamics, charge transfer, and energy transfer. A new class of photo-switchable nanoparticles was developed by blending conjugated polymer semiconductor with fullerene-based electron acceptors, and further blending with polystyrene maleic anhydride could improve the bulk fluorescence quantum yield of the nanoparticle and increase the on/off contrast in single-molecule experiments, which is critical for better localization accuracy. To understand how the dynamics of polaron in nanoparticle affects apparent photo-switching properties, single-molecule fluorescence spectra were collected from nanoparticles with different blending ratios and under various excitation laser intensities. Further modulation of the excitation laser intensity led to a transient fluorescent response consistent with previously published behavior of nanoparticles in bulk suspensions. The results of those experiments further help the development of a better physical model connecting polaron generation/recombination dynamics and photo-switching properties.
Recommended Citation
Cao, Liaoran, "Electron-Transfer Mediated Photo-Switching in Nanoparticles" (2023). All Dissertations. 3397.
https://tigerprints.clemson.edu/all_dissertations/3397