中文摘要：

制备了一种壳聚糖包覆的磁性纳米粒子, 并对其进行了表征和蛋白吸附特性研究. 首先通过共沉淀法制备了表面羧基功能化的磁性纳米粒子（MNP-COOH）, 然后通过静电相互作用将壳聚糖自组装在MNP-COOH粒子表面, 在甲醛保护氨基的情况下,利用环氧氯丙烷交联粒子表面壳聚糖上的羟基, 交联完成后脱去氨基保护剂, 制得表面富含氨基的壳聚糖包覆磁性纳米粒子（MNP-CS）. 分别使用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、傅里叶变换红外光谱仪（FTIR）、热重分析仪（TGA）、震动样品磁强计（VSM）和zeta电位仪等对制得的MNP-CS进行表征. 结果表明,壳聚糖成功地被包裹在磁性纳米颗粒表面. 颗粒可完全分散于pH=1~14的水溶液中, 形成均匀溶胶, Fe3O4磁核能抵抗0.1 mol/L的HCl溶液腐蚀. MNP-CS颗粒直径为10~20 nm, 饱和磁化值为50.05 emu/g, 剩磁和矫顽力近似为零, 具有明显的超顺磁性. 制得的磁性纳米粒子吸附BSA时呈明显的S型等温吸附特性, 单层吸附量约为300 mg/g.

英文摘要：

Chitosan-coated magnetic nanoparticles were prepared.At first,surface carboxyl functional magnetic nanoparticles （MNP-COOH） were prepared by co-precipitation.Secondly, chitosan molecules were adsorbed on the surface of particles by electrostatic interaction.The hydroxyl groups on the chitosan were then cross-linked by epichlorohydrin under the protection of primary amine groups with formaldehyde.After the amino-protecting agent were removed,the chitosan coated magnetic nanoparticles with primary amine groups on the surface were obtained.The magnetic nanopartieles were characterized by scanning electron microscopy （SEM）,X-ray diffraction （XRD）,Fourier transform infrared spectroscopy （FTIR）,thermogravimetric analysis （TGA）,vibrating sample magnetometry （VSM） and zeta potential analysis.The results showed that the magnetic nanoparticles were coated by chitosan successfully and could be completely dispersed in aqueous solutions of various pH=1~14 to form uniform sols.The magnetic cores of the paritcles are resistent to the corrosion of 0.1 mol/L HCl solution.The diameter of these nanoparticles with the saturation magnetization of 64.5 emu/g distributes between 10 and 20 nm.The remnant magnetization and coercivity of the nanoparticles were nearly zero,suggesting that it possessed a typical superparamagnetic characterization.The isotherm for the adsorption of BSA onto the MNP-CS surface was S-shaped.The maximum adsorption capacity reached 300 mg BSA/g MNP-CS.