Wiring Biohybrids for Bioelectronic Sensing and Solar Conversion

Electron flux simultaneously conveys information and energy in electro‑active systems. By wiring microorganisms to conductive materials we create biohybrid devices that sense and transform their surroundings with unprecedented speed and selectivity. I will first describe an eight‑component, post‑translationally gated electron‑transport chain engineered into Escherichia coli. Encapsulating the cells in a conductive hydrogel yields a living bioelectronic sensor that converts thiosulfate or the endocrine disruptor 4‑hydroxytamoxifen into an electrical current within 2–3 minutes, achieving mass‑transport‑limited response times even in complex river water samples.

Next, I will present an abiotic‑biotic domino platform for solar CO₂ up‑cycling. A TiO₂|Co(terpyridine)₂ photocatalyst first photoreduces CO₂ to syngas, which is immediately fermented by an adaptively evolved Clostridium ljungdahlii strain. The evolved microbe grows 2.5‑fold faster and produces C₂ chemicals 120‑fold more efficiently than the wild type, enabling continuous, light‑driven conversion of CO₂ to acetate and ethanol (0.46 mM acetate after 6 days). 

Together, these case studies showcase a general strategy: precisely wiring living cells to synthetic components to direct the flux of electrons for rapid information transfer or to channel the flux of energy and carbon for sustainable chemical manufacturing.

Host: Professor Louise Horsfall, School of Biological Sciences