Fluid-permeable enzymatic lactate sensors for micro-volume specimen

Area of Science:

• Biomedical Engineering
• Electrochemistry
• Wearable Technology

Background:

• Lactate monitoring in perspiration is crucial for health and exercise management.
• Efficient collection of small perspiration volumes is a key challenge for wearable sensors.

Purpose of the Study:

• To develop a self-powered, mesh-type enzymatic sensor for lactate detection in minimal fluid volumes.
• To integrate this sensor into an enzymatic biofuel cell for continuous monitoring applications.

Main Methods:

• Fabrication of mesh-type enzymatic electrodes on textile meshes using carbon nanotubes (CNTs) and lactate oxidase.
• Integration of a fluid-permeable anode and an air-breathing cathode into a compact enzymatic biofuel cell.
• Coating the anode with polyurethane to enhance linearity and maintain textile mesh properties.

Main Results:

• The developed sensor demonstrated a small device size (1 cm²) and fluid permeability.
• Amperometric response showed moderate linearity across a wide lactate concentration range (5 to ≥20 mM).
• The sensor functioned as a self-powered lactate sensor in a biofuel cell configuration.

Conclusions:

• The mesh-type enzymatic biofuel cell is a promising platform for continuous lactate monitoring in perspiration.
• The flexible, permeable sensor design addresses challenges in collecting and sensing small fluid volumes.
• This technology has potential applications in non-invasive health and exercise tracking.