Author ORCID Identifier
https://orcid.org/0009-0004-1734-2258
Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Julio Alvarez, Ph.D.
Abstract
Biomolecular condensates are membraneless organelles formed through liquid–liquid phase separation that compartmentalize proteins and nucleic acids to regulate cellular processes. Depending on molecular interactions and environmental conditions, condensates can transition from liquid-like to gel-like or solid-like states, processes associated with pathological protein aggregation in neurodegenerative diseases. Quantitative characterization of condensate viscoelasticity is therefore critical; however, current approaches rely primarily on optical techniques, while electrochemical methods remain largely unexplored. In this work, we investigate protein hydrogels formed from bovine serum albumin and lysozyme using cyclic voltammetry. We show that viscous and viscoelastic fluids can be distinguished by analyzing non-Fickian diffusion of dissolved electroactive molecules. A parameter α is introduced to quantify deviations from Fickian behavior. While increased viscosity reduces the diffusion coefficient without altering α (~1), viscoelastic hydrogels exhibit decreases in both the diffusion coefficient and α (< 1), indicating subdiffusive transport. These findings are consistent with particle microrheology while extending transport analysis to molecular tracers. We further study liquid-like coacervate droplets formed by poly-L-lysine and multivalent redox-active molecules using stochastic electrochemistry at ultramicroelectrodes. Single-droplet collisions generate transient current signals whose characteristics depend on composition, salt concentration, and pH. Together, these results establish electrochemical methods as a powerful and complementary approach for probing transport and viscoelastic properties in biomolecular condensates.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
4-23-2026
Comments
Revised version is submitted after committee feedback.
Embargo requested is due to two pending publications.