免疫磁性纳米微球的制备与表征

成功制备了Fe3O4磁性纳米颗粒及二甲基丙烯酸乙二醇酯-甲基丙烯酸(EGDMA-MAA)共聚物包覆的Fe3O4磁性复合微球。将吲哚美辛抗体固定在复合微球表面,形成了Fe3O4(核)/聚合物-抗体(壳)的复合免疫磁性颗粒。XRD结果表明,制备的Fe3O4的晶型为反立方尖晶石型且纯度较高;TEM表征表明Fe3O4粒径较为均匀,平均粒径为12nm;磁性复合微球的平均直径为460nm。制备的Fe3O4磁性纳米颗粒和磁性复合微球有较强的磁响应强度,其饱和磁化率分别为49.16和8.38emu/g,能够满足磁性分离的要求。FT IR验证了磁性复合微球中羧基特征峰的存在,表明羧基成功连接在磁性微球上面。通过碳二亚胺/N-羟基琥珀酰亚胺(EDC/NHS)活化法将微球表面羧基活化并成功与抗吲哚美辛抗体交联。

Preparation and characteristic of immunomagnetic microspheres

The Fe₃O₄ magnetic nanopaticales were firstly synthesized, and then EGDMA/MAA polymers coated on magnetic nanopaticales (e.g. magnetic composite microspheres) were prepared. After immobilizing antibody against indomycin on the surface of the microspheres, the formed Fe₃O₄ (core)/polymer-antibody (shell) were composite immunization microspheres.XRD testing results shows the prepared Fe₃O₄ was the cubic spinel crystal shape and high purity. Fe₃O₄ nanopaticles and magnetic composite microsphere were characterized by TEM, which showed that the average diameter were about 12 nm and 460 nm, respectively. All of these two kinds of particles have high saturated susceptibility reached to 49.16 emu/g and 8.38 emu/ g. The low residual magnetism and coercive force illustrate that they are superparamgnetism and can be used for magnetical separation. FTIR results implicated that the carboxyl groups were successful modified on the surface of magnetic composite particles. The carboxyl group were then activated by EDC/NHS method and coupled to antibody succesfully.