Electrochemical Characterization of Biomolecular Electron Transfer at Conductive Polymer Interfaces
Abstract
Bio-electrochemical systems (BESs) are promising for renewable energy generation but remain hindered by inefficient electron transfer at electrode surfaces. As the toolbox of bio-anode materials increases, rigorous electrochemical characterization of emerging materials is needed. Here, we holistically characterize the electrochemical interaction of flavin mononucleotide (FMN), an electron shuttle in biological systems and a cofactor for oxidoreductase enzymes, with the bio-inspired mixed conducting polymer poly{3-[6′-(N-methylimidazolium)hexyl]thiophene} (P3HT-Im+). The behavior of this polymer is compared to the equivalent polymer without the histidine-like imidazolium. We find improved conductivity and charge storage in imidazolium-containing polymers beyond what is explained by differences in the electroactive area. The P3HT-Im+ further shows internal charge storage but with negligible faradaic contribution, indicating that charge storage capacity may translate to improved biocatalysis non-intuitive ways. Finally, one-electron transfer is observed between FMN and glassy carbon, while a bio-similar two-electron transfer is observed for the P3HT-Im+. To our knowledge, this is the first example of a concerted two-electron transfer between FMN and an electrode interface, which we attribute to the bio-inspired, histidine-like imidazolium functional groups in the polymer. These studies demonstrate the importance of bio-relevant materials characterization when such materials are deployed in BESs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2023
- Source ID
- 10.1149/1945-7111/acb239
Entities
People
- Alec Agee
- Ariel Furst
- Gordon Pace
- Rachel A. Segalman
- Thomas Mark Gill
Organizations
- Army Research Office
- National Science Foundation
- United States Department of Energy