Crosslinked PEDOT Thin Film Electrode for Microbial Bioelectrochemical Systems

Microbial bioelectronics combines microbes and electronic devices for diverse applications including energy harvesting, chemical production, and health monitoring. The biotic-abiotic interface in bioelectronics can connect the biology and electronic worlds and facilitate cell-material communication. Materials with nice conductivity, mechanical property, and biocompatibility at the interface such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) have been employed in bioelectronics. Recent studies electropolymerized PEDOT:PSS to encapsulate microbes, but the microbe-material interaction and biofilm formation were not fully investigated. Here, we used a photocrosslinking method to coat PEDOT thin film on indium tin oxide (ITO) electrode for proliferation and immobilization of exoelectrogenic microbe, Shewanella oneidensis. The electrode was fabricated by crosslinking PEDOT:PSS with 2-hydroxyethyl acrylate under long-wavelength UV light. Microbe viability and attachment were excellent on the crosslinked thin film electrode, and the film greatly improved current density comparing to plain ITO electrode. This work studies the microbe immobilization and biofilm formation on a crosslinked PEDOT thin film electrode and can be applied to future bioelectronics design.