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利用溶剂热法和种子生长法分别合成Fe3O4磁性纳米粒子和Au@Ag核壳纳米粒子,利用静电吸附方法成功将聚乙酰亚胺(PEI)修饰到Fe3O4表面并通过N—Ag共价键将Au@Ag核壳纳米粒子组装到Fe3O4表面,制备Fe3O4/Au@Ag复合材料.通过控制Au@Ag复合粒子的加入量,来调节Fe3O4/Au@Ag复合材料的表面增强拉曼(SERS)活性.以对巯基苯胺(p-ATP)为拉曼活性探针分子来考察该复合纳米材料的SERS性能,检测限可以低至2×10-9 mol/L.同时,将该复合材料应用于农药分子福美双的检测,检测限可以低至10-6 mol/L.这种功能性复合材料既具有良好的SERS活性,又具有Fe3O4磁性内核,可以通过外加磁场实现对待测分子的分离、富集,具有更广泛的应用前景.
Fe3O4 magnetic nanoparticles and Au @ Ag core-shell nanoparticles were synthesized by solvothermal method and seed growth method respectively. Polyethyleneimine (PEI) was successfully modified onto the surface of Fe3O4 by electrostatic adsorption and Au @Ag core-shell nanoparticles were assembled on the surface of Fe3O4 to prepare Fe3O4 / Au @ Ag composites.The surface-enhanced Raman (SERS) activity of Fe3O4 / Au @ Ag composites was controlled by controlling the addition of Au @ Ag particles. The SERS properties of the composite nanomaterials were investigated with p-ATP as Raman-active probe, and the detection limit could be as low as 2 × 10-9 mol / L.Meanwhile, the composite was applied to pesticide molecules The detection limit of thiram is as low as 10-6 mol / L. This kind of functional composite material not only has good SERS activity, but also has a magnetic core of Fe3O4, which can separate, enrich, Has a broader application prospects.