A simple fluorescent probe for the fast sequential detection of copper and biothiols based on a benzothiazole derivative

Abstract

A simple benzothiazole fluorescent chemosensor was developed for the fast sequential detection of Cu2+ and biothiols through modulating the excited-state intramolecular proton transfer (ESIPT) process. The compound 1 exhibits highly selective and sensitive fluorescence “on-off” recognition to Cu2+ with a 1:1 binding stoichiometry by ESIPT hinder. The in situ generated 1-Cu2+ complex can serve as an “on-off” fluorescent probe for high selectivity toward biothiols via Cu2+ displacement approach, which exerts ESIPT recovery. It is worth pointing out that the 1-Cu2+ complex shows faster for cysteins (within 1min) than other biothiols such as homocysteine (25min) and glutathione (25min). Moreover, the compound 1 displays 160nm Stoke-shift for reversibly monitoring Cu2+ and biothiols. In addition, the probe is successfully used for fluorescent cellular imaging. This strategy via modulation the ESIPT state has been used for determination of Cu2+ and Cys with satisfactory results, which further demonstrates its value of practical applications.