Rational, modular adaptation of enzyme-free DNA circuits to multiple detection methods

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Synthetic Biology

Background:

• Enzyme-free signal amplification is crucial for developing affordable point-of-care diagnostics.
• Catalyzed hairpin assembly (CHA) is a known mechanism for enzyme-free DNA circuits with signal amplification.
• The efficiency and broad applicability of CHA for diverse analytical needs remain to be fully explored.

Purpose of the Study:

• To design and characterize a simplified DNA circuit utilizing the CHA mechanism.
• To evaluate the suitability of this simplified CHA circuit for various analytical applications.
• To demonstrate the adaptability and efficiency of CHA for molecular detection and signal amplification.

Main Methods:

• Design and optimization of a simplified DNA circuit based on catalyzed hairpin assembly.
• Application of the circuit across multiple analytical formats: fluorescent, colorimetric, and electrochemical signaling.
• Characterization of the circuit's performance, including background noise and catalytic efficiency (kcat).

Main Results:

• The optimized CHA circuit exhibited near-zero background signal.
• Achieved high catalytic efficiency with a kcat value exceeding 1 min⁻¹.
• Demonstrated successful adaptation of the circuit for detecting both RNA and small molecule analytes.

Conclusions:

• The simplified CHA DNA circuit is highly efficient and exhibits minimal background noise.
• The modular nature of the circuit allows for versatile "plug-and-play" application in various detection formats.
• Catalyzed hairpin assembly is a robust and adaptable platform for enzyme-free signal amplification in molecular diagnostics.