Eliminating Complex Matrices: A Minimalist Approach to Enzyme-Based Biosensors Using Screen-Printed Electrodes with a...

Area of Science:

• Biosensor technology
• Enzyme immobilization
• Electrochemical sensing

Background:

• Enzyme-based biosensors often require complex immobilization matrices, increasing costs and limiting scalability.
• These matrices are crucial for sensor sensitivity and stability.

Purpose of the Study:

• To develop a simplified, matrix-free lactate biosensor using direct immobilization of lactate oxidase onto screen-printed electrodes.
• To evaluate the performance, stability, and durability of this minimalist biosensor design.

Main Methods:

• Direct immobilization of lactate oxidase onto screen-printed electrodes, eliminating complex matrices.
• Performance evaluation including sensitivity, detection limit, and interference testing in human plasma.
• Long-term durability assessment with different storage strategies (aluminum packaging with desiccant vs. ambient conditions).

Main Results:

• The matrix-free biosensor achieved high sensitivity (4.22 μA dL mg^-1) and a low detection limit (3.1 mg dL^-1), outperforming matrix-based sensors.
• Stable performance was maintained for six months with simple aluminum packaging and desiccant storage.
• Significant performance degradation and underestimation of lactate occurred without appropriate packaging after two days.

Conclusions:

• Simplifying biosensor design through direct immobilization and appropriate packaging enhances performance, durability, and translational potential.
• This approach supports more accessible point-of-care lactate monitoring.
• Matrix-free configurations offer a viable alternative to complex immobilization strategies.