Microbial bioelectronic devices integrate electroactive microbes with electronics for a broad range of applications including energy generation, chemical synthesis, water remediation, and health and environmental detection. The microbe-material interface connects the biological and electronic realms via the improvement of the electronic, ionic, and molecular communication between microbes and electronics. Prior research has developed two or three-dimensional interface layers to tackle challenges such as stable microbial adhesion, efficient electron transfer, and nutrient and waste transport. However, we still lack electrode modification approaches that can be deposited easily and cheaply on an electrode surface, are amenable to patterning, and produce a significant enhancement to current densities. Here, we report a robust, conductive polymer coating that greatly enhances current densities from electroactive microbe <i>Shewanella oneidensis </i>MR-1 relative to unmodified electrodes. The coating was prepared by crosslinking a blend of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with poly(2-hydroxyethylacrylate) (PHEA) for stable microbe-material electronic communication. We found that the biocompatible PEDOT:PSS/PHEA coating supported effective extracellular electron transfer, which resulted in a significant gain in current density, and thus greatly improved microbial growth, viability, and attachment on the electrode compared to unmodified electrodes. We then demonstrated the applicability of the PEDOT:PSS/PHEA-coated electrodes in devices including microbial fuel cells, patterned bioelectronics, and organic electrochemical transistor (OECT)-based sensors. This study shows a solution-processable conductive polymer thin film that readily modifies the electrodes for diverse bioelectronics that take advantage of the high current density and microbial patterning on a surface. We envision that the PEDOT:PSS/PHEA coating can benefit the design and development of microbial bioelectronics.

Depositing and patterning PEDOT thin film electrode for microbial bioelectronics

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.