A facile AIE fluorescent probe for broad range of pH detection

Detection of pH has received more and more attention in various fields. Currently, a hot research topic is focused on how to use a facile fluorescent dye to achieve a wide range and accurate pH detection. Herein, we reported a simple fluorescence probe for pH detection with wide range and accuracy based on the Aggregation-Induced Emission (AIE) characteristics. The probe 2-oxo-N'-(2-(quinolin-8-yloxy)acetyl)-2H-chromene-3-carbo- hydrazide (CHBQ) as comprised of coumarin and quinoline as the electron donor and acceptor, N, N'-diformylhydrazine bond as the linking group, respectively. The probe displays good AIE characteristics under water content up to 99% in mixed medium. Furthermore, it can identify acid and base as fast as 30 s by color change of the solution under UV_{365 nm} lamp. The detection of the probe for pH was hardly interfered with other ions. What's more, the probe CHBQ can be designed to be a broad range test paper of pH detection, which has a great practical value.