Overcoming aggregation-induced quenching in DNA-assembled rhodamine dimers

Area of Science:

• Photochemistry
• Supramolecular Chemistry
• Biomolecular Engineering

Background:

• Collective effects in molecular aggregates are crucial for function, but aggregation-induced quenching (AIQ) can hinder studies and applications.
• Understanding and controlling AIQ is essential for harnessing the full potential of molecular aggregates.

Purpose of the Study:

• To investigate the use of DNA nanotechnology to assemble rhodamine aggregates with controllable susceptibility to aggregation-induced quenching (AIQ).
• To elucidate the structural and environmental factors governing AIQ in DNA-templated rhodamine dimers.

Main Methods:

• Assembly of rhodamine dimers using four-way DNA junctions.
• Steady-state and transient optical spectroscopy to assess AIQ.
• Optical simulations, ab initio calculations, and molecular dynamics simulations for structural analysis.

Main Results:

• Demonstrated that specific DNA configurations can either permit or inhibit AIQ in rhodamine aggregates.
• Provided structural insights into dimer packing and the influence of the DNA environment on AIQ.
• Identified a method to overcome AIQ using DNA scaffolds.

Conclusions:

• Biomolecules like DNA can be utilized to engineer the microenvironment of molecular aggregates.
• This approach offers a pathway to better understand and mitigate aggregation-induced quenching.
• DNA-templated self-assembly provides a versatile platform for controlling photophysical properties of functional materials.