On-Chip Light-Scattering Enhancement Enabled by a Microlens Array for High-Performance Single-Particle Tracking under...

Area of Science:

• Nanotechnology
• Optical Physics
• Analytical Chemistry

Background:

• Scattering-based single-particle tracking (S-SPT) enables label-free detection of nanoparticles but requires complex optical systems.
• High technical demands have limited the widespread adoption of S-SPT.

Purpose of the Study:

• To develop an on-chip microlens-based approach to enhance light scattering for S-SPT.
• To reduce the stringent requirements on optical systems for S-SPT applications.

Main Methods:

• Utilized an on-chip microlens to enhance light scattering from nanoparticles.
• Leveraged enhanced long-range optical fields and nanoparticle-microlens interactions.
• Employed a conventional bright-field microscope with incoherent light sources.

Main Results:

• Achieved a ten-fold greater enhancement range compared to existing localized field techniques.
• Demonstrated nanometer localization precision for 60 nm gold nanoparticles.
• Obtained results within a 750 µm² field of view at 200 µs exposure time.

Conclusions:

• The microlens-based S-SPT approach significantly lowers technical barriers for nanoparticle characterization.
• This advancement promotes broader accessibility and versatility of S-SPT in biosensing and other fields.