Amperometric Biosensor Based on Glutamate Oxidase to Determine Ast Activity

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensor Technology

Background:

• Aspartate aminotransferase (AST) is a key biomarker for liver function and disease.
• Accurate and rapid AST activity measurement is crucial for clinical diagnostics.
• Existing methods may have limitations in speed, cost, or sample throughput.

Purpose of the Study:

• To develop and validate a novel amperometric biosensor for quantifying AST activity.
• To optimize biosensor parameters for enhanced sensitivity and selectivity.
• To assess the biosensor's performance using biological fluid samples.

Main Methods:

• Utilized a platinum disk electrode as the transducer.
• Optimized substrate (aspartate, α-ketoglutarate) and coenzyme (pyridoxal phosphate) concentrations.
• Incorporated a poly-m-phenylenediamine membrane for improved selectivity.
• Evaluated analytical performance including sensitivity, limit of detection (LOD), and linear range.

Main Results:

• Achieved a sensitivity of 8.56 nA/min for 50 U/L AST.
• Demonstrated a low LOD of 1 U/L and a linear range of 1-110 U/L.
• Exhibited excellent stability (storage, operational, reproducibility) and high correlation (R=0.989) with spectrophotometric assays in real samples.

Conclusions:

• The developed amperometric biosensor provides a reliable and sensitive method for AST activity determination.
• The biosensor exhibits promising analytical characteristics for practical diagnostic applications.
• This technology holds potential for improving routine clinical laboratory analysis of liver function.