Quinoline-based hydrophilic flavonol fluorescent probe for specific and sensitive detection of Zn2+

Abstract

It is important to develop fluorescent sensors for the detection and quantification of Zn2+ ions related to life health issues and other problems. The 3-hydroxyflavone derivatives has excellent photophysical properties and stable ability to coordinate with metal ions. In this study, a new fluorescent probe (HQC) toward to the detection of Zn2+ based on 3-hydroxylflavone and 8-hydroxyquinoline was designed and synthesized. In ethanol–water (1:9, v/v) solution, the probe HQC displays highly selective response to Zn2+ with remarkable emission enhancement through its binding of Zn2+. The sensing of Zn2+ was nearly free from interference of other relevant metal ions. The proposed binding modes are also proved by density functional theory (DFT) calculations, IR and HRMS analysis. The detection limit for Zn2+ is calculated to be 4.99 μM. Furthermore, the probe HQC displays good biological compatibility and was employed to detect Zn2+ in zebrafish. The strong fluorescence emission could be observed in the presence of Zn2+ in living cells. These results indicate that the probe HQC possesses good potential application values in the detection of Zn2+ in environmental and biological systems.