Bi-functionalized aptasensor for ultrasensitive detection of thrombin

Area of Science:

• Biosensors
• Analytical Chemistry
• Nanotechnology

Background:

• Thrombin is a critical biomarker in hemostasis and thrombosis.
• Accurate and sensitive detection of thrombin is essential for clinical diagnostics.
• Existing detection methods often lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a novel bi-functionalized aptasensor for sensitive thrombin detection.
• To integrate electrochemiluminescence (ECL) and electrochemical impedance spectroscopy (EIS) for enhanced detection.
• To establish a robust platform for quantitative thrombin analysis.

Main Methods:

• Fabrication of a bi-functionalized aptasensor using thiol-terminated aptamers and complementary DNA on a gold electrode.
• Utilized biotin-avidin conjugation to immobilize quantum dots (QDs).
• Employed ECL and EIS techniques to monitor changes upon thrombin binding.

Main Results:

• Thrombin binding caused a decrease in ECL intensity and an increase in EIS signal due to QD detachment.
• Achieved a wide linear detection range from 10⁻¹⁰ to 10⁻³ μg mL⁻¹ for ECL and 10⁻¹⁰ to 10⁻¹ μg mL⁻¹ for EIS.
• Demonstrated a low detection limit of 10⁻¹⁰ μg mL⁻¹ (2.7 aM) with excellent selectivity and sensitivity.

Conclusions:

• The developed bi-functionalized aptasensor effectively detects thrombin with high sensitivity and selectivity.
• The combined ECL and EIS approach provides a reliable method for thrombin quantification.
• This aptasensor holds promise for clinical applications in diagnosing and monitoring coagulation disorders.