Ultrafluorogenic coumarin-tetrazine probes for real-time biological imaging

Area of Science:

• Bioorthogonal chemistry
• Fluorescence imaging
• Chemical biology

Background:

• Bioorthogonal chemistry enables selective labeling of biomolecules in complex biological systems.
• Fluorogenic probes offer a 'turn-on' signal, minimizing background noise and enabling sensitive detection.
• Existing bioorthogonal probes often lack sufficient brightness or require extensive washing steps.

Purpose of the Study:

• To develop novel ultrafluorogenic probes with significantly enhanced brightness for bioorthogonal applications.
• To utilize trans-cyclooctene (TCO)-tetrazine chemistry for rapid and efficient bioorthogonal reactions.
• To demonstrate the utility of these probes for rapid, no-wash imaging of diverse cellular targets.

Main Methods:

• Synthesis of coumarin-based fluorogenic dyes integrated with the TCO-tetrazine bioorthogonal platform.
• Exploitation of through-bond energy transfer (TBET) for maximizing fluorescence enhancement.
• Application of the probes for no-wash, time-resolved imaging of cell-surface receptors, mitochondria, and actin cytoskeleton.

Main Results:

• Developed ultrafluorogenic probes exhibiting over 11,000-fold fluorescence enhancement.
• Achieved the highest brightness enhancements reported for bioorthogonal fluorogenic dyes.
• Demonstrated rapid (seconds), no-wash imaging of cellular structures with minimal background signal and no nonspecific binding.

Conclusions:

• The novel ultrafluorogenic probes represent a significant advancement in bioorthogonal imaging technology.
• These probes enable highly sensitive and rapid detection of biological targets in vitro.
• The technology holds promise for future in vivo sensing and diagnostic applications.