Bioelectrocatalysis offers a promising approach for environmental remediation by reducing heavy metal contaminants into less harmful substances. However, its broader application is hindered by slow reaction rates, limited target range, and a scarcity of efficient electrochemically active species at electrode surfaces. Microbial electrochemical systems (MES) present an emerging solution by leveraging the metabolic capabilities of microorganisms to facilitate these redox transformations. Among them,
Shewanella oneidensis MR-1 stands out for its robust extracellular electron transfer (EET) mechanisms, enabling effective electron flow to external acceptors. To fully exploit
S. oneidensis MR-1 in MES, optimized platforms are essential to support microbial attachment and enhance electron transfer efficiency. Gold electrodes are particularly well-suited for this purpose, offering high conductivity, chemical stability, a wide electrochemical window, and compatibility with self-assembled monolayers for targeted surface functionalization.
In this work, we use S. oneidensis MR-1 as a model system to develop and optimize gold-based porous substrates for environmental bioremediation. These engineered electrodes incorporate gold nanoparticles onto porous gold surfaces to further enhance surface area and electron transfer kinetics. We also distinguish between direct and mediated electron transfer mechanisms to better understand and control bacterial electron transport processes. Our findings contribute to advancing bioelectrocatalytic platforms as sustainable and effective alternatives to traditional remediation technologies.
