Solid/Liquid/Gas Three-Phase Interface Enzymatic Reaction-Based Lactate Biosensor with Simultaneously High...

Area of Science:

• Electrochemistry
• Biosensors
• Biomedical Engineering

Background:

• Electrochemical lactate biosensors are crucial for health monitoring.
• Low oxygen levels in biological fluids limit biosensor sensitivity and detection range.
• Existing biosensors struggle with compromised oxidase enzymatic kinetics.

Purpose of the Study:

• To develop an electrochemical lactate biosensor with high sensitivity and a wide linear detection range.
• To overcome the limitations of low oxygen levels in biological samples.
• To enhance oxidase enzymatic kinetics for improved biosensor performance.

Main Methods:

• Fabrication of a solid/liquid/gas three-phase enzyme electrode.
• Immobilization of H2O2 electrocatalyst and lactate oxidase (LOx) on a superhydrophobic porous carbon substrate.
• Utilizing a three-phase system to ensure high oxygen levels in the local reaction zone.

Main Results:

• The three-phase lactate biosensor achieved a linear detection upper limit of 40 mM, a 57-fold increase from conventional systems.
• High sensitivity of 22.28 μA mM−1 cm−2 was maintained.
• A sweat lactate sensing device was successfully fabricated and tested for undiluted sweat during exercise.

Conclusions:

• The developed three-phase enzyme electrode significantly enhances oxidase enzymatic kinetics.
• This approach provides a high-performance lactate biosensor with both high sensitivity and a wide linear detection range.
• The technology offers a promising new strategy for advanced lactate sensing systems in health monitoring.