Single-Atom C-to-N Editing Unlocks Bright NIR-II J-Aggregates for Imaging Lymphatic Metastasis

Area of Science:

• Materials Science
• Biomedical Engineering
• Organic Chemistry

Background:

• Developing rational design guidelines for near-infrared II (NIR-II) J-aggregates remains a challenge.
• Existing NIR-II fluorophores often lack sufficient brightness and stability for advanced applications.

Purpose of the Study:

• To establish a single-atom skeletal editing strategy for precise control over hemicyanine dye properties.
• To enable efficient formation of bright and stable NIR-II J-aggregates for biomedical imaging.

Main Methods:

• Single-atom C-to-N skeletal editing in hemicyanine dyes.
• Systematic acceptor engineering to establish structure-assembly-property relationships.
• Phenolic hydroxyl modification to tune J-aggregation and supramolecular excitonic coupling.

Main Results:

• Achieved precise regulation of intramolecular charge distribution and intermolecular packing.
• Developed HZOE9 dye forming stable J-aggregates with emission >1000 nm and high quantum yield.
• Demonstrated in vivo applications including lymphatic imaging, metastasis visualization, and fluorescence-guided surgery.

Conclusions:

• Single-atom skeletal editing provides a powerful strategy for designing NIR-II hemicyanine fluorophores.
• Controllable supramolecular assembly is key for developing activatable NIR-II fluorophores.
• The developed fluorophores show significant potential for various biomedical imaging and therapeutic applications.