A Versatile Aggregation-induced Emission Fluorescent Probe for Visible Detection of pH

Area of Science:

• Chemical Sensing
• Materials Science
• Analytical Chemistry

Background:

• Aggregation-caused quenching (ACQ) limits the practical use of luminescent probes.
• Developing probes with aggregation-induced emission (AIE) is crucial for overcoming ACQ.
• Accurate pH detection is vital in various scientific and industrial fields.

Purpose of the Study:

• To design and synthesize a simple AIE-active fluorescent probe for sensitive and wide-range pH detection.
• To investigate the probe's performance in detecting pH based on intramolecular charge transfer (ICT).
• To demonstrate the probe's utility in visualizing pH changes and its potential for low-cost applications.

Main Methods:

• Synthesis of a donor-acceptor-donor (D-A-D) style probe incorporating electron-withdrawing and donating groups.
• Characterization of the probe's photophysical properties, including fluorescence behavior in varying water fractions.
• Evaluation of the probe's pH sensing capabilities in methanol/water mixtures and its application as a test paper.

Main Results:

• The developed probe exhibits aggregation-induced emission (AIE) characteristics.
• The probe demonstrates good fluorescence even at high water fractions (up to 90%) in MeOH/water systems.
• Successful visualization and profiling of pH detection were achieved using the probe in MeOH/water mixtures.

Conclusions:

• The AIE-active probe effectively overcomes aggregation-caused quenching for luminescent pH sensing.
• The probe offers a wide response range and high sensitivity for pH detection.
• The probe's potential for broad-range pH test paper applications highlights its practical utility and cost-effectiveness.