Leveraging lifetime information to perform real-time 3D single-particle tracking in noisy environments

Area of Science:

• Biophysics
• Optical Microscopy
• Nanotechnology

Background:

• Tracking fast-moving single particles is crucial for understanding cellular processes.
• High-background environments in biological samples limit current tracking capabilities.
• Existing methods struggle with high fluorescence and scattering common in cellular studies.

Purpose of the Study:

• To develop an advanced microscopy platform for 3D single-particle tracking.
• To overcome limitations posed by high-background noise in biological samples.
• To enable precise tracking of fast-moving particles in complex environments.

Main Methods:

• Utilized a hardware-based time-gating module capable of processing photons at 100 MHz.
• Integrated this module with a two-photon-excited 3D single-particle tracking confocal microscope.
• Employed single quantum dots as probes for proof-of-principle experiments.

Main Results:

• Demonstrated significantly improved tracking performance in high-background solutions.
• Successfully tracked single quantum dots in the presence of dye-stained cellulose.
• Achieved high sample penetration depth due to the two-photon excitation.

Conclusions:

• The developed microscopy platform enables 3D single-particle tracking in challenging environments.
• Hardware-based time-gating enhances tracking of fast-moving particles (D ≈ 3.3 µm²/s).
• This technology is valuable for researchers studying single particles in cellular and other high-background settings.