Magnetically Separable Fe3O4@Au@Tb-MOF Fluorescent Probe with Well-Designed Sandwich Structure and Metal-Enhanced Fluorescence

Abstract

Exploiting a high-performance magnetic separation probe is important for the detection of nitroaromatic compounds. Here, a novel Fe3O4@Au@Tb-BTC metal–organic framework (MOF) fluorescent probe was synthesized and used for the determination of nitroaromatic hydrocarbons. Thanks to the fluorescence enhancement of the gold nanoparticle-layer and the sheet structure of the outer Tb-BTC, the Fe3O4@Au@Tb-BTC with sandwich structure exhibits significantly higher sensitivity than Fe3O4@Tb-BTC in quantitative detection of nitroaromatic explosives. The quenching constant (Ksv) toward picric acid in ethanol is up to 5.08×104 M−1 and the limit of detection (LOD) could reach to 3.14×10−6 M. Furthermore, it can be easily to recycle by applying an external magnetic field. The unique sandwich structure makes Fe3O4@Au@Tb-MOF highly efficient and recoverable, offering broad opportunities in the field of promising probe synthesis and application.