Design,Synthesis And Properties Of Fluorescent Probes Based On Metal Ion Recognition

Fluorescent probes have the advantages of simplicity,portability,high selectivity,high temporal and spatial resolution（observable cell structure）and low cost.They are increasingly favored by the majority of scientific researchers.In the past decade,many fluorescent probes with different fluorescent groups have been reported to detect various ions.In this paper,three fluorescent probes were designed and synthesized to detect different ions.The specific contents are as follows:A novel turn-on fluorescent probe for highly selective and sensitive detection of Zn²⁺based on 4-（Dimethylamino）-2-hydroxyacetophenone was developed.Probe 1 exhibited an effectively selective and sensitive recognition towards Zn²⁺over Cd²⁺and other cations.The perfect invertibility and renewability of probe 1 for sensing Zn²⁺were also demonstrated.The detection limit of probe 1 towards Zn²⁺was calculated at very low concentration up to4.6×10^-8 mol/L.Detection mechanism of Zn²⁺ion by probe 1 was suggested through the analytical tools like UV–vis,¹H NMR titration and the DFT calculations experiments.More importantly,probe 1 was successfully used to detect zinc ions in cells and real water samples.A new easy to synthesize reaction-based probe HgL for the fluorescence signaling of Hg²⁺ions using a dithiane derivative dye.The designed probe exhibited prominent fluorescence signaling behavior towards Hg²⁺ions by the deprotection of its dithiane function to an aldehyde in an aqueous acetonitrile solution.Thus,the use of a citrate buffer allowed exclusive Hg²⁺selective signaling to be obtained in the presence of common environmentally relevant transition metal ions.The detection limit of probe HgL towards Hg²⁺was calculated at very low concentration up to 5.7×10^-7 M.The binding process was confirmed by fluorescence measurements,¹H NMR and mass spectroscopy.Moreover,the probe HgL has been successfully used to rapidly detect trace amounts of hazardous Hg²⁺ions in tap water with acceptable results and good recoveries.A highly selective probe L for fluorescence turn-on detection of Zn²⁺ion based on coumarin-quinoline schiff base derivative.Probe L has excellent water solubility.Probe L showed excellent selectivity for Zn²⁺ions in Tris buffer solution.The L-Zn²⁺complex exhibited an effectively selective and sensitive recognition towards adenosine diphosphate（ADP）over phosphate derivatives and other anions.The detection limit of probe L towards Zn²⁺and ADP was calculated at very low concentration up to 3.18×10^-7 mol/L and1.10×10^-7 mol/L respectively.It was further confirmed that probe L had potential practical applications through biological imaging of Zn²⁺and ADP in C6 cells.