"Donor-two-acceptor" dye design: a distinct gateway to NIR fluorescence

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Biophysical Chemistry

Background:

• Fluorescence methods are crucial for detecting chemical and biological analytes.
• There is a growing need for more sensitive, specific, and versatile fluorescent molecules.
• Existing fluorescent probes often lack optimal properties for advanced applications.

Purpose of the Study:

• To design and synthesize novel long-wavelength fluorogenic probes with a turn-ON mechanism.
• To develop versatile dye compounds with modular structures for tailored properties.
• To explore the potential of these probes for near-infrared (NIR) fluorescence imaging.

Main Methods:

• Design of probes based on a donor-two-acceptor π-electron system.
• Incorporation of latent donors and multiple acceptors into a modular probe structure.
• Utilizing internal charge transfer for fluorochrome formation and fluorescence emission.
• Computational studies to understand structure-property relationships.
• Confocal microscopy to assess cellular uptake and localization.

Main Results:

• Successful design and synthesis of a library of versatile fluorogenic probes.
• Demonstrated fluorescence emission in the near-infrared (NIR) region.
• Established a turn-ON mechanism based on internal charge transfer.
• Computational studies correlated well with experimental observations.
• Confocal imaging revealed lysosomal penetration of a selected dye in HeLa cells.

Conclusions:

• The developed donor-two-acceptor based probes exhibit desirable properties for fluorescence detection.
• The turn-ON mechanism and NIR emission make these dyes suitable for sensitive bioimaging.
• These novel fluorogenic probes show significant potential for in vivo imaging applications.