Coarse-grained model simulation-guided localized DNA signal amplification probe for miRNA detection

Area of Science:

• Biomolecular Engineering
• Nanotechnology
• Computational Biology

Background:

• Enzyme-free DNA signal amplification is crucial for detecting low-abundance biomarkers.
• Localized DNA reaction units enhance signal amplification by increasing molecular collision probability.
• Limited understanding of structure-function relationships hinders the performance of localized DNA probes.

Purpose of the Study:

• To investigate the impact of localized distance and flexibility on the performance of DNA enzyme-free signal amplification circuits.
• To develop a coarse-grained molecular model for simulating the dynamic behavior of DNA reaction units in Localized Catalytic Hairpin Assembly (LCHA).
• To provide mechanistic insights and structure-function relationships for designing efficient localized DNA probes.

Main Methods:

• Utilized a coarse-grained molecular model to simulate the dynamic behavior of DNA reaction units within the LCHA circuit.
• Investigated the effects of varying localized distances and flexibility on reaction performance.
• Validated simulation findings by designing and testing optimized LCHA probes.

Main Results:

• The most efficient LCHA probe, guided by simulations, achieved a 28-fold increase in sensitivity compared to free CHA, with a miR-21 detection limit of 16 pM.
• The least effective LCHA probe showed a modest 7-fold improvement in sensitivity.
• Optimized probes successfully differentiated cancer cells from normal cells based on miR-21 expression levels, demonstrating quantification ability.

Conclusions:

• Elucidating mechanistic insights and structure-function relationships in localized DNA probes can significantly improve biosensing performance.
• Informed probe design based on simulation data can save time and reduce costs for researchers.
• This work has broad applications in DNA nanotechnology for biosensing, biocomputing, and bionic robots.