Microbial bioelectronic devices take advantage of the functionality of microbes and electronics for a variety of applications including energy harvesting, chemical production, environmental monitoring, and health-related technologies. The cell-material interface bridges the gap between the biological and electronic worlds and provides communication between microbes and electronic devices. While a number of studies have used conductive polymers such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as interface materials, a simple approach to fabricate patterned, polymer-modified thin-film electrodes to deposit multiple strains of microbes is lacking. Specifically, there is a need for robust, conductive, and biocompatible interface layers for interfacing electronic devices with electroactive microbes such as Shewanella oneidensis (S. oneidensis) which can generate electron currents for applications in energy harvesting, synthesis, or chemical sensing. Here, we report an effective biocompatible and conductive polymer interface layer that significantly enhances current fluxes when interfaced with S. oneidensis. The electrode was prepared by UV crosslinking PEDOT:PSS with 2-hydroxyethyl acrylate. We found that the PEDOT:PSS film greatly enhanced microbe viability and attachment on the electrode relative to unmodified electrodes, and the PEDOT:PSS film significantly improved biotic current density compared to the unmodified electrode. We patterned the polymer thin film via plasma treatment, and the patterned electrode supported stable immobilization of different strains of microbe, i.e. S. oneidensis MR-1 with and without green fluorescence protein (GFP), on the specific area on the same substrate. We implemented the thin film electrodes as microbial fuel cells to power a high-voltage LED light as a proof of principle device. This work demonstrates a simple, solution-processable conductive polymer blend for modifying and patterning electrodes that will be useful to bioelectronic applications that benefit from high current fluxes and patterning of microbes on a surface.

PEDOT based thin film electrode for microbial bioelectronics

ACS Fall 2021

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