An Eu3+-functionalized metal–organic framework (Eu@Zn-MOF) for the highly sensitive detection of rotenone in serum

Abstract

In this work, a metal–organic framework (MOF) (Zn-MOF) with free sulfonate groups (–SO₃⁻) on its organic ligands is constructed in the first step via a solvothermal synthesis method. Then, based on the coordination post-synthetic modification (PSM) strategy, an Eu³⁺-functionalized hybrid material (Eu@Zn-MOF) with excellent fluorescence properties is successfully prepared. Notably, the prepared Eu@Zn-MOF can serve as a visual probe to specifically recognize and detect rotenone based on the fluorescence quenching effect. In addition, Eu@Zn-MOF as a sensor of rotenone exhibits some other outstanding properties, including good selectivity and an anti-interference ability, high sensitivity (LOD = 2.31 × 10⁻⁷ mol L⁻¹), a fast response speed and reusability, which contribute to developing its real-life applications. Moreover, the possible sensing mechanisms of Eu@Zn-MOF towards rotenone are confirmed to be a combination of dynamic quenching and competitive absorption. This is the first time the determination of rotenone based on a fluorescence detection method has been realized.