A Dual-Capture and Dual-Output 3D DNA Walker System Integrated with Ligases Enables Ultrasensitive Detection of...

Area of Science:

• Biotechnology
• Molecular Biology
• Nanotechnology

Background:

• DNA walkers are programmable tools for signal amplification in biosensing.
• Existing enzyme-free DNA walkers have limited performance, and enzyme-dependent ones face compatibility issues.

Purpose of the Study:

• To develop an efficient, enzyme-free 3D DNA walker with dual capture and dual output capabilities.
• To create a highly sensitive and specific biosensing system for single nucleotide polymorphism (SNP) detection using ligase chain reaction (LCR).

Main Methods:

• An enzyme-free 3D DNA walker system based on entropy-driven circuit cycling reaction technology was designed.
• LCR products were used as driving strands for the DNA walker, interacting with immobilized track strands and walking legs on gold nanoparticles.
• A dual signal capture mechanism was implemented, with each track strand carrying two signal chains for enhanced amplification.

Main Results:

• The biosensing system achieved ultrasensitive detection of mutant targets (MT) down to 30.3 aM.
• It successfully distinguished heterozygous samples with a mutation frequency as low as 0.01%.
• The system was validated for genotyping and mutation abundance assessment in soybean leaf genomes.

Conclusions:

• A novel enzyme-free 3D DNA walker with dual capture and dual output capabilities was pioneered.
• An ultrasensitive genotyping tool was developed, offering significant potential for genetic research and applications.
• This technology provides strong support for advancing genetic research and diagnostics.