Programmable Fc-encoded DNA tile-cube capture enables a thrombin-activated ratiometric ECL/SERS biosensor via a...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Molecular Biology

Background:

• Accurate thrombin detection is vital for coagulation assessment but challenged by matrix interference and signal variations.
• Existing methods struggle with reliable quantification of ultralow thrombin levels.
• A novel biosensor integrating multiple advanced technologies was developed to overcome these limitations.

Purpose of the Study:

• To develop a sensitive and reliable biosensor for ultralow thrombin detection.
• To overcome challenges in thrombin quantification, including matrix interference and signal drift.
• To establish an internally referenced and extensible platform for protein biosensing.

Main Methods:

• Development of a ratiometric electrochemiluminescence/surface-enhanced Raman scattering (ECL/SERS) biosensor.
• Integration of Fc-encoded DNA tiles, DNA-cube scaffold, and CRISPR/Cas12a module on a modified electrode.
• Utilizing a programmable capture-release strategy triggered by thrombin recognition.

Main Results:

• The biosensor demonstrated a wide detection range (1 × 10^-7 to 1 × 10^-1 nM) with a low detection limit (0.064 µM).
• Anti-correlated ECL and SERS signals were integrated for accurate ratiometric quantification (Q = I_ECL/I_SERS).
• High recovery rates (96.8%-104.0%) were achieved in serum spike-recovery tests, confirming analytical accuracy.

Conclusions:

• A programmable capture-release strategy was established, converting thrombin recognition into CRISPR/Cas12a-mediated cleavage.
• The developed biosensor provides a sensitive, internally referenced, and extensible platform for protein detection.
• This approach offers a significant advancement in ultralow protein quantification for biomedical applications.