An interparticle relatively motional DNA walker and its sensing application

Area of Science:

• Nanotechnology
• Molecular Biology
• Biochemistry

Background:

• DNA molecular machines are DNA self-assemblies with quasi-mechanical movement capabilities.
• These machines are increasingly utilized in biosensing, drug delivery, and biocomputing.
• Existing DNA walkers have limitations in motion freedom and signal accumulation.

Purpose of the Study:

• To report the concept and operation of an interparticle relatively motional DNA walker.
• To develop a sensitive and robust detection platform for specific targets.
• To explore the potential of this new DNA walker in clinical diagnosis.

Main Methods:

• Functionalization of gold nanoparticles (AuNPs) with DNAzyme sequences (walking particles, WPs) and fluorophore-labelled substrate sequences (track particles, TPs).
• Target-triggered unlocking of walking strands, leading to hybridization with track strands.
• DNAzyme-catalyzed cleavage of track strands, releasing fluorophores and inducing interparticle motion.

Main Results:

• The interparticle motional mode allows for improved moving freedom and area, resulting in high continuity and large signal accumulation.
• Demonstrated high sensitivity for detecting Zika virus RNA fragments (ZIKV-RNA) with a detection limit of 118 pM.
• The DNA walker components exhibit stability, enabling reliable detection in biological fluids.

Conclusions:

• The constructed DNA walker presents a new, free, and robust interparticle motion mode.
• This system offers enhanced sensitivity and signal accumulation for molecular detection.
• The DNA walker holds significant potential for applications in clinical diagnosis and biosensing.