Abstract: Chitosan was grafted onto the surface of Fe3O4 magnetic nanoparticles fabricated by a chemical coprecipitation method by using (3-chloropropyl) trimethoxysilane as a coupling agent. The modified magnetic nanoparticles were characterized by infrared spectroscopy (FTIR)，X-ray diffraction (XRD)，scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The adsorption properties of the magnetic nano-adsorbent for BSA were investigated under different conditions，including adsorption time，pH and concentration of bovine serum albumin. The size of nanoparticles was about 20 nm，and chitosan made up 15.40% of the weight of the modified Fe3O4 magnetic nanoparticles. Compared with Fe3O4 nanoparticles，chitosan modified nanoparticles showed higher BSA adsorption capacity.

Key words: nanoparticles, surface, bovine serum albumin, chitosan, protein

摘要： 采用化学共沉淀法制备磁性Fe3O4纳米粒子，以（3-氯丙基）三甲氧基硅烷为偶联剂将壳聚糖共价键合到磁性Fe3O4纳米粒子的表面，通过红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）及热重分析（TGA）对其进行了表征。主要研究了不同影响因素（吸附时间、pH值、牛血清白蛋白浓度）下壳聚糖修饰的磁性纳米粒子对牛血清白蛋白（BSA）的吸附性能。结果得到壳聚糖修饰的磁性Fe3O4纳米粒子粒径为20 nm左右，壳聚糖在磁性Fe3O4纳米粒子表面的接枝率为15.40%。研究表明：在不同条件下，与未修饰的磁性Fe3O4纳米粒子相比，经壳聚糖修饰的Fe3O4纳米粒子对BSA均表现出较强的吸附能力。

关键词: 纳米粒子, 表面, 牛血清白蛋白, 壳聚糖, 蛋白质