中文摘要：

利用磁性纳米粒子Fe_3O_4表面的聚多巴胺（PDA）对银离子的吸附作用,采用种子诱导法制备了载银磁性纳米粒子（PDA-Fe_3O_4@Ag）。采用UV-Vis（紫外-可见）光谱对PDA-Fe_3O_4@Ag纳米粒子的制备过程进行了分析,采用FTIR（红外光谱）、XRD（X射线衍射仪）、TEM（透射电镜）和VSM（振动样品磁强计）等手段对所得的PDA-Fe_3O_4@Ag粒子进行表征;研究了PDA-Fe_3O_4@Ag对4-硝基苯酚还原反应的催化作用,还测试了其抗菌性能。结果表明,纳米金种子的存在是制备PDA-Fe_3O_4@Ag纳米粒子的关键;在外加磁场作用下该磁性催化剂可以容易地从反应体系中分离,经多次循环使用后仍具有良好的催化性能;此外PDA-Fe_3O_4@Ag纳米粒子具有杀菌性能,且经磁分离回收循环利用5次后仍呈现对金黄色葡萄球菌较好的杀菌效果。

英文摘要：

Silver-deposited magnetic nanoparticles（PDA-Fe_3O_4@Ag） were prepared though the seed-mediated method exploiting the adsorption of silver ions by the polydopamine（PDA） which was coated on the surface of Fe_3O_4.The preparation process was studied using UV-Vis spectra and the prepared nanoparticles were characterized with several analytical techniques including Fourier-transform infrared（FT-IR）,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,and vibrating sample magnetometer（VSM）.The catalytic action on the reduction of 4-nitrophenol and the antibacterial property of PDA-Fe_3O_4@Ag were studied.The result indicates that the existence of gold seeds is the key to prepare PDA-Fe_3O_4@Ag nanoparticles.The magnetic catalyst can be separated easily from the reaction system by applied magnetic field,and still has good catalytic performance after repeated recycling.In addition,PDA-Fe_3O_4@Ag nanoparticles exhibit bactericidal properties,and still shows good bactericidal effect on S.aureus after recycling use for 5 times.