文摘
A novel selective fluorescent chemosensor based on an 8-hydroxyquinoline-appended fluorescein derivative (L1) was synthesized and characterized. Once combined with Cu2+, it displayed high specificity for sulfide anion. Among the various anions, only sulfide anion induced the revival of fluoresecence of L1, which was quenched by Cu2+, resulting in 鈥渙ff鈥搊n鈥?type sensing of sulfide anion. What鈥檚 more, the sensor was retrievable to indicate sulfide anions with Cu2+, and S2鈥?/sup>, in turn, increased. With the addition of Cu2+, compound L1 could give rise to a visible pink-to-yellow color change and green fluorescence quenching. The resulting yellow solution could change to pink and regenerate to green fluorescence immediately upon the addition of sulfide anion; however, no changes were observed in the presence of other anions, including CN鈥?/sup>, P2O74鈥?/sup>, and other forms of sulfate, making compound L1 an extremely selective and efficient sulfide chemosensor. The signal transduction occurs via reversible formation鈥搒eparation of complex L1Cu and CuS. What鈥檚 more, the biological imaging study has demonstrated that the chemosensor can detect sulfur anions in biological systems at a relatively low concentration.
