Redox Polymer Networks for Encapsulation of Electroactive Bacteria and Mediated Charge Transport

Electronic devices that interface living, electroactive bacteria with conductive and semiconductive polymers have broad applications for power generation, sensing, and chemical manufacture. However, these devices are limited by several challenges related to interfacing electroactive bacteria with electrochemical devices, including efficient charge transport between bacteria and electrodes, materials for robust encapsulation, and amplifying the generally weak signals provided by the electroactive bacteria. Here, we report that redox polymers with pendant electroactive groups can enhance extracellular electron transfer (EET) while simultaneously encapsulating bacteria within a polymer network. The polymers are prepared by grafting redox-active groups onto a chitosan polymer and crosslinking using ionic or covalent interactions. These redox polymers are compatible with different bacteria, including synthetically engineered E. Coli and L. plantarum, and can be used to build novel bioelectronic sensors. We study the charge transport mechanisms of these redox polymers and compare them to charge transport in other conductive and semiconductive polymers. We also show that these materials can be patterned and printed onto an electrode. This work demonstrates a new class of electroactive polymer for use in living bioelectronic devices.