Preparation 4 '-Quinolin-2-yl- [2, 2 '; 6 ', 2 ''] terpyridine as a ratiometric fluorescent probe for cadmium ions and zinc ions in aqueous

摘要

A ratiometric fluorescent probe, 4'-Quinolin-2-yl-[2,2';6',2 ''] terpyridine (QTPY), is designed and synthesized successfully for cadmium ions (Cd2+) and zinc ions (Zn2+) detection. The purity and structure of QTPY are confirmed by LC-MS, (HNMR)-H-1 and C-13 NMR. The probe exhibits good sensitivity for Cd2+ and Zn2+ in dimethyl formamide-water (DMF-H2O) mixed solvent (F-w 40% V/V). Its fluorescence intensity is enhanced significantly with good linearity with the increase of Cd2+ (0 - 5 mu mol.L-1) and Zn2+ (6 - 10 mu mol.L-1) at 520 nm. The detection limit (LOD) of the fluorescent probe reaches 3.5 x 10(-8) mol.L-1 to detect Cd2+. The probe shows good selectivity upon Cd2+ and Zn2+ among many common metal ions. Meanwhile, Cu2+ interferes seriously with the fluorescent probe under given conditions. Furthermore, the QTPY probe also exhibits excellent characterization for detecting Cd2+ in a natural lake water.