Simpler fluorescent probe for homocysteine selective detection

A simpler and selective turn-on fluorescent probe namely 4-(benzothiazol-2-yl) phenyl 2-chloroacetate ester 2 was synthesized by chloro‑acylation of 4-hydroxyphenyl benzothiazole (4-HBT). The probe 2 was investigated for the detection of biothiols among amino acids. The addition of Homocysteine (Hcy) selectively induced significant fluorescence enhancement and the detection limit was determined to be 7.7 × 10−6 M. The probe 2 conserves simple structure, and %atom economy. Paper strip tests were carried out to explore the potential application for naked-eye fluorescence detection of Hcy under UV lamp. We expect the presented probe 2 will offer a valuable approach to acquire selective detection and discrimination of Hcy over other biothiols especially cysteine (Cys).