Simple way to correct the drift in surface-coupled optical tweezers using the laser reflection pattern

Area of Science:

• Biophysics
• Nanotechnology
• Biotechnology

Background:

• Surface-coupled optical tweezers are crucial for studying biological motion at the nanoscale.
• Drift between the optical trap and surface can interfere with precise measurements.

Purpose of the Study:

• To present a simple, low-cost method for active and passive drift correction in surface-coupled optical tweezers.
• To enhance the resolution and long-term stability of optical tweezer measurements.

Main Methods:

• Utilized video tracking of laser reflection patterns and reference beads for drift correction.
• Employed Allan deviation analysis to assess resolution and stability.
• Applied the method to DNA stretching experiments.

Main Results:

• Achieved sub-nanometer resolution and stability for trapped beads over a wide averaging time range (0.002-100 s).
• Demonstrated sub-nanometer resolution through step measurements.
• Obtained 1-2 nm extension resolution and >120 s stability in DNA stretching experiments under constant force.

Conclusions:

• The developed method offers an accessible approach to achieve nanometer resolution and long-term stability for surface-coupled optical tweezers.
• This technique improves the reliability of nanoscale measurements in biological applications.
• Facilitates advanced studies of molecular mechanics and dynamics.