A Fluorescent Probe with Aggregation‐Induced Emission for Detecting Alkaline Phosphatase and Cell Imaging

Alkaline phosphatase (ALP) is associated with many diseases, and its accurate detection is of great significance. Fluorescent compounds with aggregation-induced emission (AIE) feature show beneficial advantages for serving as fluorescent probes. Herein, an AIE-active "turn on" probe for ALP detection was synthesized through incorporating a strong electron-withdrawing group (cyano) in the middle and the recognition moiety phosphate group at the end, thereby rendering a D-A-D structure with a relatively high conjugation degree and good water solubility. It was found that the probe TPE-CN-pho is highly sensitive to ALP in aqueous solution. In the presence of ALP, the hydrophilic phosphate group on the probe is rapidly removed, resulting in a decrease in water solubility and subsequent formation of aggregates, thereby achieving aggregation-induced emission. Moreover, the probe TPE-CN-pho has also been successfully applied to imaging ALP in living cells.