【作者】 吴文兵； 王显祥； 单志； 杨婉身；

【Author】 Wu Wen-bing~(1,2) Wang Xian-xiang~1 Dan zhi~1 Yang Wan-shen~(*1) (1.College of Life Science,Sichuan Agricultural University,Ya’an,Sichuan,625014;2.Department of Environmental Science,Kashgar Teacher’s College,Kashgar,Xingjiang,844000)

【机构】 四川农业大学 生命科学与理学院； 喀什师范学院生命与环境科学系；

【摘要】 在共沉淀法制备油酸包被的 Fe₃O₄的基础上,用分散聚合法合成了一种表面富含氨基功能基团的磁性粒子,电位滴定结果表明,氨基磁性粒子表面氨基基团含量达486μmol/g 微球。利用透射电镜、X 射线衍射仪、振动样品磁强计和傅立叶变换红外光谱仪对磁性微球进行了表征,表明合成出的氨基磁性纳米粒子磁响应性强、粒度小、离径分布窄。用该磁性微球固定化了木瓜蛋白酶,固定化最佳条件为给酶量1.2mg/mL,戊二醛浓度5%,固定化时间 4小时;固定化酶较溶液酶具有更低的 Km 值（0.489%:3.412%）,更好的酸碱（6.8:7.2） 和温度耐受性（77℃:67℃）,操作和储藏稳定性也得到了很大提高。更多还原

【Abstract】 The oleic acid coated Fe₃O₄ was prepared by chemical coprecipitation method first, then amino-group Functionalized magnetic nanoparticles was synthesized by dispersion polymerization.Electrometric titration result indicated that,the surface amino group of magnetic microsphere reached 486μmol/g.The magnetic nanoparticles were characterized by means of transmission electron microscope （TEM）,X-ray diffractometer （XRD）,Vibrating Sample Magnetometer （VSM） and Fourier Transform Infrared Spectrometer （FTIR）.The amino microsphere was applied to immobilized papain.The optimal immobilization condition is that: 1.2mg/ml for proportion of enzyme,5% for concentration of glutaraldehyde and 4 hours for immobilization time.Compared to free enzyme immobilized enzyme had lower Km （0.489%: 3.412%）,better tolerance of acid base （6.8:7.2） and temperature （77℃:67℃）,the stability of manipulation and preservation enhanced greatly too.更多还原