A Novel ESIPT Phthalimide-Based Fluorescent Probe for Quantitative Detection of H₂O₂

Hydrogen peroxide (H₂O₂) is a majority reactive oxygen species (ROS) and acts as an essential role in pathological and physiological processes. Therefore, the development of quantitative detection of methods for H₂O₂ is necessary. Here, we constructed of a novel simple fluorescence probe for detection of H₂O₂ based on the excited-state intramolecular proton transfer process. The probe utilized a phthalimide derivative as the fluorophore and selected phenylboronic acid as the recognition site for H₂O₂. In response to H₂O₂, the probe exhibited 63-fold fluorescence intensity enhancement, a low detection limit (8.4 × 10^-8 M), and large Stokes shift (111 nm). In addition, the probe displayed high selectivity for H₂O₂ over other ROS. Moreover, the probe was successfully employed for imaging of H₂O₂ in living cells.