A General Method to Develop Highly Environmentally Sensitive Fluorescent Probes and AIEgens.

Area of Science:

• Materials Science
• Biochemistry
• Organic Chemistry

Background:

• Environmentally sensitive fluorescent probes are crucial for biological studies.
• The twisted intramolecular charge transfer (TICT) mechanism is key for many probes.
• Existing probes based on coumarins and rhodamines have limited sensitivity due to weak TICT.

Purpose of the Study:

• To develop a general method for engineering highly environmentally sensitive fluorescent probes.
• To enhance the TICT tendency in fluorophores for improved sensitivity.
• To create novel probes with aggregation-induced emission (AIE) characteristics.

Main Methods:

• Replacing dialkylated amino donors with N-methylpyrrole groups to enhance TICT.
• Synthesizing a series of colorful fluorescent probes.
• Evaluating probe sensitivity to polarity and viscosity.
• Assessing aggregation-induced emission (AIE) properties.
• Demonstrating probe utility in bioimaging and protein detection.

Main Results:

• A new method successfully engineered highly environmentally sensitive fluorescent probes.
• The novel probes exhibit outstanding sensitivity to polarity (up to 191x turn-on) and viscosity (up to 14x turn-on).
• The probes display distinct aggregation-induced emission (AIE) characteristics.
• Successful application in wash-free bioimaging and protein detection was demonstrated.

Conclusions:

• The N-methylpyrrole modification strategy effectively enhances TICT and probe sensitivity.
• These novel probes offer significant advantages for sensitive bioimaging and detection.
• This molecular design approach is expected to drive the development of new environmentally sensitive probes.