A nanoplatform Of Eu3+ @ citric acid-functionalized UiO-66: Facile preparation and highly-sensitive detection For Fe3+ and Cr2O72- ions in an aqueous system

A novel fluorescent sensor material of Eu3+ @ Citric acid-functionalized UiO-66 (denoted as Eu3+@UiO-66-CA) was prepared successfully via a two-step post synthetic modification towards UiO-66. The as-obtained Eu3+@UiO-66-CA presented the characteristic emission of Eu3+ ions (λex = 270 nm), which could be used for rapidly detecting Fe3+ and Cr2O72- ions by luminescence quenching in aqueous solution. The detection process for Fe3+ ion (detection limit, 18.1 μM) and Cr2O72- ion (detection limit, 8.5 μM) exhibited the high selectivity and excellent anti-interference ability. Systematic investigations were employed to make clear the mechanism of fluorescence quenching after adding Fe3+ and Cr2O72- ions. Moreover, the Eu3+@UiO-66-CA was also used for the determination of Fe3+ and Cr2O72- ions in the Yellow River and tap water.