Preliminary study of real-time fiber optic based protein C biosensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunosensors

Background:

• Protein C (PC) deficiency is a critical condition linked to severe thrombotic events.
• Accurate and rapid diagnosis of PC deficiency is essential for timely clinical intervention.
• Existing diagnostic methods may lack the speed and sensitivity required for real-time monitoring.

Purpose of the Study:

• To develop and validate an immuno-optical biosensor for diagnosing protein C deficiencies.
• To enable real-time monitoring of protein C concentrations in patient samples.
• To compare different antibody immobilization techniques and assess fiber regeneration methods.

Main Methods:

• Development of an immuno-optical biosensor utilizing a tapered quartz fiber coated with anti-PC monoclonal antibodies.
• Comparison of direct antibody immobilization versus an avidin-biotin bridge method for enhanced signal detection.
• Evaluation of a calcium chloride (CaCl2) elution step for regenerating the biosensor fiber.

Main Results:

• The biosensor demonstrated the ability to detect protein C levels as low as 0.1 microg/mL in buffer.
• Avidin-biotin immobilization significantly increased signal intensity by up to 470% compared to direct immobilization.
• The CaCl2 elution step improved fiber lifetime by approximately 50%, indicating effective regeneration.

Conclusions:

• The developed immuno-optical biosensor shows high sensitivity and specificity for detecting protein C.
• The avidin-biotin method offers superior performance for antibody immobilization in this biosensor system.
• Further development could lead to an automated, multi-blood factor analyzer for clinical diagnostics.