Fluorescent determination of zinc by a quinoline-based chemosensor in aqueous media and zebrafish

Abstract A quinoline-based fluorescence sensor QDTD was developed for Zn 2+ . QDTD can detect Zn 2+ by fluorescence turn-on. Detecting limit (0.27 μM) of QDTD for Zn 2+ was far below WHO standard (76.0 μM). For the practical application, compound QDTD could be used to determine Zn 2+ in real samples and applied to the test kit. More importantly, QDTD was expertly applied for Zn 2+ imaging in HeLa cells and zebrafish with good membrane-permeability. Detection mechanism of Zn 2+ ion by compound QDTD was suggested through the analytical tools like 1 H NMR titration, ESI-MS, Job plot, fluorescent and UV–vis titration, and theoretical calculations, and through the synthesis and applications of a model compound AAQA .