Nanoscale membranes that chemically isolate and electronically wire up the abiotic/biotic interface

Area of Science:

• Bioelectrochemical Systems
• Nanotechnology
• Catalysis

Background:

• Bioelectrochemical systems efficiently synthesize chemicals but suffer from inefficiencies due to physical separation of microbial and abiotic catalysts.
• Chemical incompatibilities, toxicity, and ohmic losses hinder the scalability of current bioelectrochemical systems.

Purpose of the Study:

• To develop a novel bioelectrochemical system architecture that overcomes limitations of existing designs.
• To enable efficient electrochemical coupling between microbial and inorganic catalysts without detrimental cross-reactions or ohmic losses.

Main Methods:

• Electrochemical coupling of the microbial catalyst *Shewanella oneidensis* with a SnO₂ anode.
• Utilized a 2-nm-thick silica membrane functionalized with molecular wires to bridge the microbial and inorganic catalysts.
• The membrane facilitated electron flow while preventing small molecule transport.

Main Results:

• Achieved efficient electron flow (0.51 μA cm^-2) from microbial catalysts to the inorganic anode through the silica membrane.
• Successfully blocked small molecule transport, preventing cross-reactions and chemical incompatibilities.
• Demonstrated a modular architecture that avoids ohmic losses.

Conclusions:

• The developed modular bioelectrochemical system architecture effectively couples microbial and inorganic catalysts.
• This approach circumvents chemical incompatibilities and ohmic losses, paving the way for scalable bioelectrochemical applications.
• Introduces significant design flexibility for future advancements in bioelectrochemical systems.