Constructing a Highly Sensitivity SERS Sensor Based on a Magnetic Metal–Organic Framework (MOF) to Detect the Trace of Thiabendazole in Fruit Juice

Substrate materials possessing high sensitivity and storage stability are vital for the practical analytical applications of surface-enhanced Raman scattering (SERS) techniques. In this work, SERS substrate material (Fe3O4@UiO-66-NH2@Au) on a magnetic metal–organic framework (Fe3O4@UiO-66-NH2) decorated with gold nanoparticles (AuNPs) was constructed. The as-prepared SERS substrate combined the properties of the abundant hotspots between the AuNPs and the excellent adsorption performance of UiO-66-NH2 for trace molecules. Meanwhile, the presence of Fe3O4 can be helpful to separate quickly, and the generation of the coffee ring effect was weakened under the action of an external magnetic field. The results showed that the new substrate materials have excellent SERS performance. The substrate material was used for TBZ detection; it exhibited good linearity in the range from 0.025 to 2 ppm, and the limit of detection (LOD) could be down to 6.5 ppb. The Raman signal intensity of the substrate material was stable after 22 days of storage at room temperature. We constructed a sensitive, stable, and rapid method based on SERS for TBZ detection in this work, which also has great potential for the detection of food and environmental pollution in practical applications.