The α, β-unsaturated pyrazolone-based fluorescent sensor with red emission and its application for real-time monitoring hypochlorite in cancer cells and zebrafish

Fluorescent sensors have been the most commonly applied with drug discovery projects and delivery systems, as well as screening the chemical catalysts in synthetic chemistry. α, β-unsaturated pyrazolone and its derivatives have been widely developed in medicinal chemistry and in synthetic chemistry. Hence, a novel fluorescent sensor BODIPY-Pyra was explored based on α, β-unsaturated pyrazolone and BODIPY fluorophore. BODIPY-Pyra had a weak red emission (600 nm) because of rotation of CC bond. However, an enviromental restriction of TICT promoted the red fluorescence enhancement in glyceryl alcohol. Especially, α, β-unsaturated pyrazolone skeleton presented the good reactivity, which afforded the fluorescent change of BODIPY-Pyra through the chemical reaction. It's beneficial for monitoring drug delivery and chemical reaction based on CC associated and stimulated linker by fluorescence assay. To explore the potential application of BODIPY-Pyra, the response towards hypochlorite was studied as a model in cancer cells and zebra fish. The results showed that BODIPY-Pyra could respond selectively and sensitively (LOD = 172 nM) towards hypochlorite among ROS and RSS. A 320 folds fluorescent enhancement at 520 nm was observed within 60s. Moreover, it could detect the intracellular hypochlorite in cancer cells, even endogenous hypochlorite in living zebra fish without drug induction. Noteworthy, the fluorescent sensor BODIPY-Pyra might provide a potential platform by fluorescent assays to the HTS of prodrug and chemical catalyst by the chemical reaction of unsaturated pyrazolone skeleton.