Electrochemical aptamer sensor for thrombin detection based on Au nanoneedle and enzymatic ascorbic acid oxidization

Area of Science:

• Biosensors
• Nanomaterials
• Electrochemistry

Background:

• Human alpha-thrombin is a significant biomarker in various physiological and pathological processes.
• Development of sensitive and specific detection methods for thrombin is crucial for clinical diagnostics.

Purpose of the Study:

• To develop a novel aptamer-based sandwich-type electrochemical sensor for the detection of human alpha-thrombin.
• To synthesize and characterize gold nanoneedles for sensor fabrication.
• To evaluate the sensor's performance in terms of sensitivity, specificity, and applicability to real samples.

Main Methods:

• Synthesis of gold nanoneedles via electrodeposition on a polycarbonate template.
• Immobilization of thiolated thrombin aptamer I as a capture probe.
• Sandwich assay format using biotinylated aptamer II as a detection probe.
• Enzymatic signal amplification with streptavidin-conjugated alkaline phosphatase (SA-ALP).
• Detection of ascorbic acid produced by SA-ALP using differential pulse voltammetry.

Main Results:

• The sensor demonstrated a linear detection range for thrombin from 0.24 nM to 150 nM.
• A low detection limit of 0.1 nM (at 3 sigma) was achieved.
• The developed aptasensor exhibited high sensitivity, specificity, and rapid detection capabilities.
• Successful application of the sensor for thrombin detection in complex real samples was demonstrated.

Conclusions:

• The aptamer-based sandwich electrochemical sensor offers a promising platform for sensitive and specific thrombin detection.
• The use of gold nanoneedles and enzymatic amplification enhances sensor performance.
• This assay is suitable for rapid, simple, and reliable thrombin quantification in biological samples.