An Indole-Based Fluorescent Chemosensor for Detecting Zn²⁺ in Aqueous Media and Zebrafish

An indole-based fluorescent chemosensor IH-Sal was synthesized to detect Zn²⁺. IH-Sal displayed a marked fluorescence increment with Zn²⁺. The detection limit (0.41 μM) of IH-Sal for Zn²⁺ was greatly below that suggested by the World Health Organization. IH-Sal can quantify Zn²⁺ in real water samples. More significantly, IH-Sal could determine and depict the presence of Zn²⁺ in zebrafish. The detecting mechanism of IH-Sal toward Zn²⁺ was illustrated by fluorescence and UV-visible spectroscopy, DFT calculations, ¹H NMR titration and ESI mass.