Universal Electrode Based on Ferredoxin-NADP⁺ Oxidoreductase Enables Enzymatic Biofuel Cells With Broad Substrate...

Area of Science:

• Bioelectrochemistry
• Enzyme immobilization
• Nanomaterials for energy

Background:

• Enzymatic biofuel cells (EBFCS) are limited by enzyme specificity on electrodes.
• Developing universal electrodes is crucial for expanding substrate utilization in EBFCS.

Purpose of the Study:

• To design a universal electrode for enzymatic biofuel cells.
• To enable electron transfer from diverse substrates using a novel immobilization strategy.

Main Methods:

• Immobilization of ferredoxin-NADP+ oxidoreductase (FNR) using bacterial cellulose (BC), carbon nanotubes (CNTs), and silver nanowires (AgNWs).
• Coupling the universal electrode with NADPH-dependent malic enzyme and glucose dehydrogenase.
• Measuring electricity generation from malic acid and glucose.

Main Results:

• Electricity generation was achieved using malic acid and glucose as substrates.
• Open-circuit voltages reached 79.36 mV (malic acid) and 75.8 mV (glucose).
• Product accumulation (pyruvate and gluconate) reached 0.30 mM and 0.25 mM, respectively, after 12 hours.

Conclusions:

• The developed universal electrode effectively utilizes diverse substrates for electricity generation in biofuel cells.
• The strategy enables efficient electron transfer via NADPH, broadening the applicability of EBFCS.
• This approach offers a promising pathway for enhancing biofuel cell technology.