Single-Molecule Sandwich Aptasensing on Nanoarrays by Tethered Particle Motion Analysis

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Biology

Background:

• High-throughput single-molecule analysis demands rapid, simple, and sensitive detection methods for health and environmental applications.
• Existing techniques may not meet the increasing need for precision at the single-molecule level.

Purpose of the Study:

• To develop a novel aptasensor for sensitive, direct detection of single target molecules.
• To utilize a single-DNA-molecule biochip and aptamer-based sandwich assay for real-time analysis.

Main Methods:

• Development of a single-DNA-molecule biochip for parallel tethered particle motion (TPM) analysis.
• Integration of aptamers with nanoparticles tethered to a surface via DNA for target recognition.
• Real-time monitoring of particle motion changes indicative of target binding.

Main Results:

• Successful development of an aptasensor capable of detecting single target molecules via a sandwich assay.
• Demonstrated direct detection and quantification of targets with a picomolar limit of detection for thrombin.
• Achieved an analytical range spanning three orders of magnitude for target concentration.

Conclusions:

• The developed aptasensor offers a sensitive and direct method for single-molecule detection.
• This technique holds promise for advancing rapid diagnostics in health and environmental monitoring.
• The combination of TPM, DNA biochips, and aptamers provides a powerful platform for molecular analysis.