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以水为分散介质,氯金酸为金源,柠檬酸钠为还原剂制备了纳米金粒子,然后将其与表面有氨基修饰的Fe3O4/SiO2磁性纳米粒子进行自组装,制备Au/Fe3O4/SiO2磁性纳米复合粒子.采用X射线衍射仪(XRD)、紫外可见吸收光谱(UV-Vis)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)对样品进行表征.结果表明,柠檬酸钠的用量对纳米金粒子的大小有影响,不同粒径的金纳米粒子对应于UV-Vis上吸收峰的峰宽不同,而且吸收峰的位置也随着复合粒子的形成而发生变化;Au/Fe3O4/SiO2复合粒子在外磁场的作用下,能够与反应体系快速分离,易于循环使用.“,”In this research,gold nanoparticles are prepared using water as dispersion medium,chloroauric acid as source of gold and sodium citrate as a reducing agent,then gold nanoparticles are self-assembled with Fe3O4/SiO2 magnetic nanoparticles which surface are modified with amino group using APS(3-aminopropyltrimethoxysilane),thus Au/Fe3O4/SiO2 magnetic nanocomposite are successfully obtained.Samples are characterized by X-ray diffraction(XRD),UV-visible absorption spectra(UV-Vis),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).The results demonstrate that the size of gold nanoparticles is influenced by the amount of sodium citrate.The width of the absorption peak of gold nanoparticles in UV-visible absorption spectra varied with the particle size,moreover,the absorption position of Au nanoparitlce shows red-shift due to surface touching with Fe3O4/SiO2,where electron deficiency was formed.Besides,Au/Fe3O4/SiO2 composite particles can be separated easily under an external magnetic field,which is beneficial for repeated use.