LAUSR

Abstract A new quinoline-based fluorescent chemosensor MDCQA was designed and synthesized for the relay sensing of Zn2+ and S2−. MDCQA showed turn-on fluorescence toward Zn2+, and the resulting complex was able to detect S2− among the competitive anions by turn-off fluorescence. Detecting limits (0.06 μM and 2.33 μM) for zinc ion and sulfide were remarkably below WHO guidelines (76.0 μM for zinc ion and 14.7 μM for sulfide). In addition, sensor MDCQA successfully operated for imaging Zn2+ in live zebrafish larvae and quantifying it in real water samples. The detecting properties and mechanisms of MDCQA toward zinc ion and sulfide were demonstrated by UV–vis and fluorescence spectroscopy, NMR titration, DFT calculations and ESI-Mass.