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Updated: May 16, 2026

Translating Extracellular Electron Transfer Activities with Organic Electrochemical Transistors
Published on: January 31, 2025
Electrochemical communication between microbial cells and electrodes via osmium redox systems
Kamrul Hasan1, Sunil A Patil, Dónal Leech
1Department of Biochemistry and Structural Biology, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
Abstract:
Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.
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