Synthesis Of Fe₃O₄/Noble Metal Composite And Its SERS Properties

Along with the fast development of nanotechnology, the magnetic iron oxide nanomaterials have a wide range of applications because of its unique physical properties.Fe3O4has been widely used in the areas such as targeting drug carrier, magnetic resonance imaging(MRI) contrast agent, cancer thermotherapy due to its high biological compatibility. Surface enhanced Raman spectroscopy (SERS), as one kind of detection means with high sensitivity, has been extensively applied in multiple areas, including chemistry, material, biology and so on. With the progress of science and technology, the requirements for the SERS substrate have been improved. Therefore, the multi-functional and recyclable substrates have aroused general concern. In this paper, we have synthesized and characterized several kinds of Fe3O4nanoparticles with special morphologies in the purpose of applying the Fe3O4NPs as a template to construct ideal SERS substrate; Fe3O4/noble metal composite materials was prepared based on the high magnetic saturation intensity of Fe3O4NPs, and it can be used as recyclable SERS substrate.This paper includes the following chapters.In chapter I, the magnetic Fe3O4NPs was simply introduced, firstly, including the special properties, preparation and application. Then, the fabrication and application of Fe3O4/noble metal composite materials were systematically expounded. Finally, we stated systematically the development, mechanism and research progress about substrate of SERS.In the second chapter, the FeCl3-Na2CO3-ascorbic acid hydrothermal system was chosen as the research object. The FeCO3micron particles with a variety of special morphology were successfully prepared by adjusting the reactant concentration, reaction time and other conditions. And Fe3O4nano-materials with peanut shape and ellipsoid shape were further obtained. Experiments showed that these materials had good solubility in water, and excellent magnetic response under an applied magnetic field.In chapter III, the Fe3O4/Au@Ag iron oxide/noble metal nanocomposite was fabricated via polyethylenimine(PEI) modifying Fe3O4magnetic NPs. And the composite was used to the SERS detection for p-ATP and thiram. Experiments showed that the material has a very good SERS activity. In addition, the composite can be used as recycled recycling SERS substrate due to its superparamagnetism.