(677a) Enzyme-Inspired Conductive Polymers Enhance Charge Transfer from Electroactive Microbes

Electrochemical systems that incorporate microbes are uniquely poised to meet challenges in renewable energy and sustainable chemical synthesis. By integrating electrochemical and whole-cell catalysis, these technologies simultaneously combine high energy efficiency with the ability to catalyze complicated multistep reactions. However, a major barrier to their use at scale is sluggish electron transfer between cells and electrodes, reducing overall efficiency.

By engineering a conductive polymer electrode, we boost the overall efficiency of microbe-electrode electron transfer. This enhancement is due to improved kinetics for mediator oxidation at the electrode. We further discover that these kinetic benefits result from an enzyme-like catalytic mechanism, in which an undesirable intermediate is thermodynamically destabilized to allow a higher efficiency reaction to dominate. Finally, we connect this catalytic property to the unique electrochemical structure of our polymer material. These results establish a new bio-inspired strategy for enhancing microbial electrocatalysis and establish material design principles for next generation electrode materials.