Nanometer-precision linear sorting with synchronized optofluidic dual barriers

Area of Science:

• Physics
• Nanotechnology
• Biophysics

Background:

• Optical trapping of nanoparticles has advanced significantly, typically operating above 10^-8 N/m stiffness.
• Sorting sub-50-nm nanoparticles with single-nanometer precision remains a challenge in conventional optical trapping.
• Advanced micromanipulation applications are limited by the inability to precisely sort small nanoparticles.

Purpose of the Study:

• To demonstrate precise sorting of nanoparticles using optical trapping in the challenging loosely overdamped regime.
• To enable single-nanometer precision manipulation of nanoparticles with radii from 30 to 150 nm.
• To explore new opportunities in tumor targeting, intracellular imaging, and sorting of viruses and DNA.

Main Methods:

• Utilizing a quasi-Bessel optical profile within a microchannel.
• Coordinating optical force and flow drag force to achieve a loosely overdamped regime (stiffness, 10^-10 to 10^-8 N/m).
• Establishing a damping roadmap to synchronize forces for controlled particle manipulation.

Main Results:

• Successfully sorted single gold nanoparticles (30-50 nm radii) and polystyrene nanoparticles (100-150 nm radii) with single-nanometer precision.
• Demonstrated precise separation, positioning, and microscopic oscillation of nanoparticles.
• Achieved nanoparticle manipulation in the challenging loosely overdamped regime.

Conclusions:

• The study reveals a novel damping scenario enhancing understanding of particle kinetics in optical systems.
• This method offers unprecedented capabilities for sorting nanoparticles with high precision.
• The findings open new avenues for applications in biomedicine and nanotechnology, including tumor targeting and virus sorting.