Organosulfur/Selenium-Based Highly Fluorogenic Molecular Probes for Live-Cell Nucleolus Imaging.

Area of Science:

• Chemical Biology
• Molecular Imaging
• Organic Chemistry

Background:

• Developing selective fluorescent probes is crucial for advanced bioimaging.
• Organochalcogen compounds offer unique photophysical properties for sensing applications.
• Targeting specific cellular components like nucleoli requires tailored probe design.

Purpose of the Study:

• To develop novel fluorogenic cationic organochalcogens for selective RNA imaging.
• To investigate the mechanism of enhanced fluorescence upon RNA interaction.
• To demonstrate the utility of these probes for high-contrast nucleoli bioimaging.

Main Methods:

• Synthesis of novel organoselenium and organosulfur based fluorescent probes.
• Evaluation of probe selectivity and photophysical properties in aqueous solutions.
• Confocal microscopy for high-contrast imaging of cell nucleoli.
• Multiscale simulation studies to understand structure-interaction relationships.

Main Results:

• Developed cell-permeable, red-emissive probes with high quantum yield upon RNA binding.
• Demonstrated selective and high-contrast imaging of cell nucleoli.
• Simulation studies revealed RNA-induced rotational freezing and planarization enhance fluorescence via intramolecular charge transfer.
• Identified the impact of heavy-chalcogens on improved emissive properties.

Conclusions:

• Fluorogenic cationic organochalcogens are effective tools for selective RNA and nucleoli imaging.
• Probe design incorporating cyclic sidearms and heavy-chalcogens enhances fluorescence and selectivity.
• These probes offer a promising platform for advanced cellular bioimaging.