A Graphene-Based Enzymatic Biosensor Using a Common-Gate Field-Effect Transistor for L-Lactic Acid Detection in Blood...

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Lactate is a key biomarker for various medical conditions including ischemia and respiratory failure.
• Accurate lactate monitoring is crucial for timely diagnosis and patient management.
• Existing detection methods may lack the sensitivity, specificity, or cost-effectiveness for widespread use.

Purpose of the Study:

• To develop and characterize a novel graphene-based biosensor for detecting L-lactic acid.
• To functionalize graphene with lactate dehydrogenase for enhanced selectivity and stability.
• To evaluate the sensor's performance in buffer solutions and human plasma.

Main Methods:

• Graphene surface functionalization with lactate dehydrogenase using Nafion, chitosan, and glutaraldehyde.
• Fabrication of graphene-based biosensors.
• Testing sensor response linearity across different L-lactic acid concentrations.
• Performing interference studies with common biological molecules (ascorbic acid, uric acid, glucose).
• Assessing sensor stability and operational lifetime.

Main Results:

• The biosensor demonstrated linear responses to L-lactic acid concentrations in both buffer and plasma.
• Minimal interference was observed from ascorbic acid, uric acid, and glucose.
• The functionalized graphene showed good stability for up to 50 days, with stable device operation for 12 days.
• The developed sensor exhibits promising performance for monitoring L-lactic acid.

Conclusions:

• Graphene-based biosensors offer a viable platform for sensitive and selective L-lactic acid detection.
• The functionalization strategy enhances sensor stability and minimizes interference.
• This technology has the potential for integration into low-cost, flexible sensors for point-of-care applications.