Voltammetric aptasensor for thrombin by using a gold microelectrode modified with graphene oxide decorated with...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Thrombin is a key protein in blood coagulation, making its accurate detection crucial for diagnosing and monitoring various hemostatic disorders.
• Existing methods for thrombin detection often face limitations in sensitivity, specificity, or complexity.
• Development of highly sensitive and specific biosensors is essential for clinical diagnostics and research.

Purpose of the Study:

• To develop a sensitive and specific electrochemical aptasensor for the quantitative determination of thrombin.
• To utilize signal amplification strategies for enhanced detection performance.
• To validate the aptasensor's efficacy in complex biological matrices like human serum.

Main Methods:

• Synthesis of silver nanoparticles decorated graphene oxide (AgNP-GO) via chemical reduction.
• Modification of AgNP-GO with thrombin-binding aptamer 1 (TBA1) to create a signaling probe.
• Immobilization of thrombin-binding aptamer 2 (TBA2) on a gold electrode surface.
• Formation of a sandwich complex (TBA2-thrombin-TBA1-AgNP-GO) for detection.
• Electrochemical signal measurement using square wave voltammetry.

Main Results:

• The developed aptasensor demonstrated high sensitivity for thrombin detection, with a linear range from 0.05 to 5 nmol·L⁻¹.
• A low detection limit of 0.03 nmol·L⁻¹ (S/N=3) was achieved, indicating superior sensitivity.
• The aptasensor exhibited excellent specificity, unaffected by the presence of other proteins.
• Successful application in determining thrombin concentrations in spiked human serum samples was demonstrated.

Conclusions:

• The developed electrochemical aptasensor offers a sensitive, specific, and reliable platform for thrombin detection.
• The combination of aptamers, silver nanoparticles, and graphene oxide provides effective signal amplification.
• This aptasensor shows significant potential for clinical diagnostics and biomedical research applications involving thrombin analysis.