Development of an amperometric screen-printed galactose biosensor for serum analysis

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensor Technology

Background:

• Galactosemia diagnosis requires accurate measurement of circulating galactose levels.
• Existing diagnostic methods may have limitations in speed, cost, or accessibility.
• Development of rapid and reliable biosensors is crucial for early disease detection.

Purpose of the Study:

• To develop and optimize a disposable amperometric biosensor for quantifying galactose in human serum.
• To evaluate the biosensor's performance characteristics, including sensitivity, linear range, and limit of detection.
• To assess the biosensor's applicability and precision in real serum samples for galactosemia diagnosis.

Main Methods:

• Fabrication of a screen-printed carbon electrode (SPCE) modified with cobalt phthalocyanine (CoPC), cellulose acetate (CA) membrane, and immobilized galactose oxidase (GALOX).
• Optimization of biosensor parameters: enzyme loading (2U GALOX), temperature (35°C), pH (7.0), and buffer strength (50mM phosphate buffer).
• Amperometric detection of galactose in serum using the optimized GALOX-CA-CoPC-SPCE biosensor.

Main Results:

• Optimal biosensor response achieved under specific conditions: 2U GALOX, 35°C, pH 7.0, 50mM phosphate buffer.
• High sensitivity (7.00μAmM⁻¹cm⁻²) and a wide linear range (0.1–25mM) with a low limit of detection (0.02mM).
• Excellent precision (1.10% for unspiked, 0.11% for spiked serum) and recovery (99.9%) in serum analysis, suitable for galactosemia diagnosis (>1.1mM).

Conclusions:

• The developed disposable amperometric biosensor (GALOX-CA-CoPC-SPCE) is a sensitive and precise tool for serum galactose measurement.
• The biosensor's performance characteristics are well-suited for the clinical diagnosis of galactosemia in infants.
• This technology offers a promising approach for rapid and reliable point-of-care testing for galactosemia.