DNA concentration modulation on supported lipid bilayers switched by surface acoustic waves

Area of Science:

• Biophysics
• Materials Science
• Nanotechnology

Background:

• Developing methods for precise molecular arrangement on supported lipid bilayers is crucial for advanced biosensing and screening platforms.
• Current techniques for manipulating molecules within fluid membranes are limited in their ability to create dynamic, addressable arrays.

Purpose of the Study:

• To investigate the use of in-plane surface acoustic shear waves (SAWs) for the lateral accumulation and patterning of double-stranded DNA on cationic supported lipid bilayers.
• To demonstrate the dynamic generation of spatially addressable molecular arrays on a fluid membrane surface.

Main Methods:

• Applying in-plane surface acoustic shear waves (SAWs) to electrostatically bound double-stranded DNA on cationic supported lipid bilayers.
• Utilizing fluorescently labeled DNA to visualize segregation into stripe patterns and accumulation in SAW antinodes.
• Superposing orthogonal SAW sources to create dynamic checkerboard-like DNA arrays.

Main Results:

• DNA segments segregated into stripe patterns with a spatial frequency matching the SAW periodicity (~10 μm).
• A 10-fold accumulation of DNA molecules was achieved in SAW antinode regions.
• Dynamic checkerboard arrays of DNA were generated by superposing orthogonal SAW fields.
• Pattern relaxation time was measured at 0.58 s, suggesting lipid diffusion dominates over DNA self-diffusion.

Conclusions:

• In-plane surface acoustic waves provide an effective method for the dynamic, spatially controlled accumulation of DNA on supported lipid bilayers.
• The ability to create addressable molecular arrays on demand opens new possibilities for on-chip screening and binding assays.
• The observed relaxation dynamics highlight the interplay between acoustic forces and membrane properties in molecular patterning.