Design of Optimized PEDOT‐Based Electrodes for Enhancing Performance of Living Photovoltaics Based on Phototropic Bacteria

Abstract Living photovoltaics represent a growing class of microbial devices that are based on whole cell–electrode interactions. The limited charge transfer at the cell–electrode interface represents a significant bottleneck in realizing an efficient technology. This study focuses on the development of poly(3,4‐ethylenedioxythiophene) (PEDOT)‐based electrodes that are electrosynthesized in the presence of a sodium dodecyl sulphate (SDS) dopant. Potentiodynamic and potentiostatic electrochemical techniques, as well as scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, and theoretical modelling of the electropolymerization transient, are employed to create and characterize PEDOT electrodes under various conditions. The electrodes are able to capture photosynthetically derived current under multiple light–dark cycles when interfaced with Synechocystis sp. PCC 6803. In the presence of the Synechocystis, the PEDOT electrodes show a sixfold and twofold enhancement over conventional graphite electrodes for both mediatorless and K₃Fe(CN)₆‐mediated conditions, respectively. The ability of these electrodes to enhance extracted photocurrent for both direct and indirect electron transfer mechanisms provides a versatile platform for improving various microbial devices.