Purple bacteria & 3-D redox hydrogels for bioinspired photo-bioelectrocatalysis.

Abstract

To date, a major challenge for the implementation of intact bacterial cells in photo-bioelectrochemical systems remains the hindered extracellular electron transfer. Herein, we focus on purple bacteria, photosynthetic microorganisms particularly interesting for bioelectrochemical systems development thanks to their versatile metabolisms. While soluble monomeric redox mediators have been proven as an effective system for electron transfer mediation, their application in the field is not preferable due to toxicity and unwanted release into the environment. We report an abiotic/biotic photo-anode where a bio-inspired redox mediating system is implemented in a 3-D geometry allowing to "electrically wire" intact bacterial cells. The 3-D photo-anode decreased the overpotential required for harvesting photo-excited electrons, operating at +0.073 V vs. SCE. Accordingly, the overpotential is greatly reduced compared to a pioneering Os-redox polymer reported in literature, which required operation at +0.303 V vs. SCE. These results pose the basis for further development of bio-photoanodes for light powered biosensing and power generation.

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Identifiers

DOI

10.1002/cssc.201902116

Journal

ChemSusChem

Year

2020