Preparation Of Monodisperse P(St/AA) Composite Nanospheres With High Fe₃O₄ Content And Their Biology Applications

In this paper, we focused on the synthesis of monodisperse carboxylated superparamagnetic polymer composite nanospheres with high magnetite content by a one-step miniemulsion copolymerzation. And the effect of the different surface modifications of Fe3O4 nanoparticles on the morphologies of the composite nanospheres were analyzed. Furthermore, the bio-application of these resulting carboxylated superparamagnetic polymer composite nanospheres was primarily investigated.First, the composite nanospheres were produced by a convenient one-step miniemulsion copolymerzation in the presence of undecylenic aid /oleic acid–costabilized Fe3O4 nanoparticles. Under different experimental conditions, the monodisperse superparamagnetic polymer composite nanospheres, diameter from 41 to163 nm with high magnetite content (78wt.-%) and 0.058 to 0.25 mmol carboxyl groups/g nanospheres were successfully produced. The effects of various polymerization parameters, such as the magnetic fluid concentration, the acrylic acid concentration, the surfactant concentration and the pre-emulsification process on the properties of the composite nanospheres were analyzed in detail. Second, the surface chemistry of Fe3O4 nanoparticles played a crucial role in the morphology of the synthesized carboxylated supermagnetic polymer nanospheres. Therefore, we mainly investigated the effect of different surface-modification agents undecylenic aid and oleic acid on the morphologies of the composite nanospheres. And theory about the resulting morphologies was also studied.Last, the carboxylated superparamagnetic polymer composite nanospheres were used in magnetic immunity quantitative test of HCG. The results showed that such composite nanospheres were applicable in immunity quantitative test, and would have bright prospects in biomedical applications.