A new quercetin@ZIF-8composite as turn-on fluorescent sensor for selective and sensitive detection of Al3+ ions

A fluorescent chemosensor (QCT@ZIF-8)based on ZIF-8 and quercetin was designed and synthesized.QCT@ZIF-8 retained the framework structure of ZIF-8 and also exhibited highly thermal and chemical stability. QCT@ZIF-8 started to decompose after 570 ℃ and its crystal structure remained unchanged after soaking in different solvents. QCT@ZIF-8 showed highly selective turn-on fluorescence response towards Al3+ in ethanol with very low detection limit. The fluorescence intensity of QCT@ZIF-8 increased linearly with the increase of Al3+concentration with the detection limit for Al3+ as low as 0.58 μM. The selective fluorescence response of QCT@ZIF-8 towards Al3+was attributed to the unique pore structure and chelating effect of quercetin with Al3+. The satisfactory recovery of QCT@ZIF-8 in detection of Al3+ in actual water samples proved that QCT@ZIF-8can be used as a fluorescent chemosensor for the identification and detection of Al3+ in environmental and water samples.