A novel covalent post-synthetically modified MOF hybrid as a sensitive and selective fluorescent probe for Al3+ detection in aqueous media.

A modified MOF named UiO-66-NH2-SA was synthesized based on the covalent post synthetic attachment of the MOFs (UiO-66-NH2) and salicylaldehyde via a Schiff-base reaction. The as-prepared functionalized UiO-66-NH2-SA not only maintains its structural integrity during the PSM process, but also shows excellent luminescence and good fluorescence stability in water. It was further utilized as a novel fluorescent probe for detecting of Al3+. The fluorescence intensity of UiO-66-NH2-SA increased linearly upon increasing the concentration of Al3+ in the range of 0-500 μM with a detection limit of 6.98 μM. The possible mechanism is discussed. This study presents a new ratiometric and colorimetric Al3+ fluorescent sensor. The good fluorescence stability of UiO-66-NH2-SA in aqueous media, the low detection limit and the broad linear in sensing Al3+ indicate its high potential in practical applications.