The ESIPT fluorescent probes for N₂H₄ based on benzothiazol and their applications for gas sensing and bioimaging

Two novel fluorescent chemosensors based on the benzothiazole derivative were designed, synthesized, and used as a selective hydrazine sensor in a DMSO and HEPES buffer mixture (10 mM, pH 7.4)(9:1, v/v). The probes displayed high sensitivity and selectivity of hydrazine after adding more than 18 types of analyte. The application of the probes in detecting N₂H₄ in living cells and in the gas state was also investigated. The single crystal X-ray study of the fluorescent sensor both before and after treatment with N₂H₄ confirmed the proposed mechanism based on excited state intramolecular proton transfer (ESIPT).