A novel 4-hydroxypyrene-based “off–on” fluorescent probe with large Stokes shift for detecting cysteine and its application in living cells

Abstract

This paper reports a novel fluorescent probe 4-acrylatepyrene (PYAC) based on 4-hydroxypyrene, which can effectively detect cysteine (Cys). The probe PYAC uses acrylate moiety as a recognition site and has relatively high selectivity and sensitivity for Cys with the detection limit of 0.062 μM. After treatment with Cys, PYAC exhibits “off–on” switching property and large Stokes shift (171 nm). Due to nucleophilic addition and specific intramolecular cyclization, it exhibits higher selectivity for Cys than other amino acids and common ions, including homocysteine (Hcy) and glutathione (GSH) with similar structures to Cys. The recognition mechanism has been characterized by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance spectroscopy (1H NMR). Anti-interference test and pH influence test display it is suitable for detecting Cys in living cells. Finally, the probe PYAC has been successfully applied to cell imaging with negligible cytotoxicity.