Target catalyzed hairpin assembly for constructing a ratiometric electrochemical aptasensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Molecular Biology

Background:

• Protein detection is crucial for disease diagnosis and monitoring.
• Existing methods often lack sensitivity, selectivity, or require complex procedures.
• Aptasensors offer a promising alternative for rapid and specific biomolecule detection.

Purpose of the Study:

• To develop a novel dual-signaling amplified aptasensor for enhanced protein detection.
• To utilize target-catalyzed hairpin assembly for signal amplification.
• To establish a sensitive, selective, and regenerable platform for thrombin detection.

Main Methods:

• Design of a dual-signaling aptasensor using two DNA hairpins (H1 and H2).
• H1 modified with methylene blue (MB) contains the thrombin aptamer sequence.
• H2 modified with ferrocene (Fc) is complementary to H1, enabling target-catalyzed hairpin assembly and signal amplification.
• Ratiometric detection using the ratio of Fc and MB signals (IFc/IMB).

Main Results:

• Achieved a significantly low detection limit of 41 fM for thrombin.
• Demonstrated amplified signal generation compared to single-signaling approaches.
• Exhibited high selectivity and good regenerability of the aptasensor.
• The dual-signaling aptasensor provided a ratiometric response for quantitative analysis.

Conclusions:

• The developed dual-signaling aptasensor offers a highly sensitive and selective platform for protein detection.
• Target-catalyzed hairpin assembly is an effective strategy for signal amplification in aptasensors.
• This ratiometric electrochemical aptasensor provides a robust and repeatable method for quantitative analysis of target proteins.