Enzymes hosted in redox-active ionically cross-linked polyelectrolyte networks enable more efficient biofuel cells

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Redox mediators are crucial for efficient electron transfer between enzymes and electrodes in bioelectrochemical systems.
• Developing novel redox mediators is key to advancing bioelectrochemical device performance.

Purpose of the Study:

• To present an alternative redox mediation approach using a novel osmium complex-modified branched polyethyleneimine (BPEI).
• To investigate the formation and performance of electroactive assemblies incorporating this redox polyelectrolyte and glucose oxidase (GOx).

Main Methods:

• Synthesis of colloidal particles from BPEI crosslinked with phosphate and functionalized with an osmium complex.
• Formation of electroactive assemblies using layer-by-layer (LbL) assembly or one-pot drop-casting (OPDC).
• Investigation of NaCl's effect on film formation and catalytic current.

Main Results:

• Colloidal particles (ca. 1 μm) were successfully formed and combined with glucose oxidase (GOx).
• Addition of NaCl significantly enhanced film formation and catalytic current.
• The bioanode demonstrated a power output of 148 μW per nmol of mediator.

Conclusions:

• The developed redox polyelectrolyte offers a new route for creating effective electroactive assemblies.
• Ion interactions with the polyelectrolyte are critical for optimizing performance.
• This approach represents a significant advancement for bioelectrochemical devices utilizing redox mediators and enzymes.