Interchromophoric Interactions Determine the Maximum Brightness Density in DNA Origami Structures

Area of Science:

• Nanotechnology
• Biophysics
• Materials Science

Background:

• Ideal point light sources require small size and high brightness.
• Fluorescent light sources need homogeneity and stable photophysical properties.
• Dye aggregation compromises fluorescent properties, limiting applications.

Purpose of the Study:

• To utilize DNA origami as a scaffold for dense dye molecule arrangement.
• To investigate dye-dye interactions and photophysical properties at high densities.
• To determine optimal labeling density on DNA origami without compromising dye performance.

Main Methods:

• Arrangement of ATTO647N dyes in a dense pixel array using DNA origami.
• Systematic alteration of dye-dye distances in single base pair increments.
• Single-molecule level probing of dye-dye interactions, intensity, and fluorescence lifetime.

Main Results:

• Strong fluorescence quenching observed at small dye-dye distances.
• Reduced quenching and increased molecular dynamics with increasing dye separation.
• Significant impact of energy transfer processes, including singlet-dark-state-annihilation, even in weak coupling regimes.

Conclusions:

• DNA origami enables controlled arrangement of dyes, mitigating aggregation issues.
• Understanding dye-dye interactions is critical for optimizing dense labeling strategies.
• Findings facilitate the development of bright, homogeneous DNA origami nanobeads for advanced imaging and biophysics.