Rolling-circle amplification detection of thrombin using surface-enhanced Raman spectroscopy with core-shell...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Thrombin is a key biomarker in hemostasis and thrombosis.
• Accurate and sensitive detection of thrombin is crucial for diagnosing and monitoring various clinical conditions.
• Existing detection methods often lack the required sensitivity or specificity.

Purpose of the Study:

• To develop an ultrasensitive surface-enhanced Raman spectroscopy (SERS) sensor for thrombin detection.
• To leverage rolling-circle amplification (RCA) to enhance the SERS signal through increased "hot-spots".
• To evaluate the sensor's performance in complex biological matrices like serum.

Main Methods:

• Fabrication of SERS probes: Gold nanoparticle@Raman label@SiO2 core-shell nanoparticles.
• Immobilization of thrombin aptamers on magnetic beads (MBs).
• In situ rolling-circle amplification (RCA) triggered by thrombin binding, leading to long DNA templates for SERS probe attachment.

Main Results:

• The developed SERS sensor achieved ultrasensitive detection of thrombin in the range of 1.0×10⁻¹² to 1.0×10⁻⁸ M.
• A remarkably low detection limit of 4.2×10⁻¹³ M was obtained.
• The sensor demonstrated robust performance and reliability in real human serum samples.

Conclusions:

• The developed SERS sensor based on RCA-increased "hot-spots" offers a highly sensitive and specific method for thrombin detection.
• This approach significantly amplifies the SERS signal by involving numerous probes in each recognition event.
• The sensor shows great potential for clinical applications in diagnosing and managing thrombotic disorders.