Journal article
Determining Redox Thermodynamics and Kinetics in Coacervates
Meeting abstracts (Electrochemical Society), v MA2026-01(58), pp 2247-2247
07 Jul 2026
Abstract
Coacervates are suggested to be the evolutionary precursor to enzymes due to their interesting similarities, the most significant being they both form unique microenvironments capable of accelerating reaction kinetics. While this phenomenon has been extensively explored, insight into how reactant, transition state, and product energies are altered within the droplet remains an active area of research. An under explored method of evaluating these energetic states is temperature dependent electrochemistry, that can quantify redox enthalpies, entropies, and Gibbs energy. In this work, we use ferri/ferrocyanide, a well-behaved redox couple that has been proposed to be an essential oxidizing agent in prebiotic Earth, to investigate the microenvironment created by the coacervation of poly-L-lysine and poly-uridylic acid. Partitioning into the coacervate causes an oxidative shift, which temperature-dependent experiments reveal is due to a 40 J/mol K and an 8 kJ/mol increase in reaction entropy and enthalpy, respectively. We attribute the change in entropy to water’s highly structured hydrogen-bonding network within the droplets and, subsequently, around the redox probe. Further, we reveal via in situ Raman measurements that the change in reaction enthalpy is due to the destabilization of the product, ferrocyanide, within the ionic coacervate phase. After establishing reaction thermodynamics, we determined kinetic changes via Koutecký-Levich analysis to better understand if the ET rate constant is affected by confinement within the biological condensates. Coupling this technique with temperature dependence we hope to go a step further and quantify the activation energy inside and outside of the coacervate to lend insight into whether coacervates could act as biological catalysts for primordial life. Figure 1
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Details
- Title
- Determining Redox Thermodynamics and Kinetics in Coacervates
- Creators
- Gala Rodriguez - University of California, Santa BarbaraNicholas B. Watkins - Los Alamos National LaboratoryElizabeth Lee - University of California, Santa BarbaraXagros Faraji - University of California, Santa BarbaraLior Sepunaru - University of California, Santa Barbara
- Publication Details
- Meeting abstracts (Electrochemical Society), v MA2026-01(58), pp 2247-2247
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- A.J. Drexel Nanomaterials Institute
- Other Identifier
- 991022207178204721