Preparation of Fe_3O_4@Au nano-composites by self-assembly technique for immobilization of glucose oxidase  

作　　者：WANG XianXiang HUANG Shuo Shan Zhi YANG WanShen 

机构地区：[1]College of Life Science and Science, Sichuan Agricultural University, Ya'an 625014, China [2]College of Chemistry, Sichuan University, Chengdu 610041, China

出　　处：《Chinese Science Bulletin》2009年第7期1176-1181,共6页

基　　金：Supported by the Science Foundation of Sichuan Province, China (Grant No. 2005A033);Science Foundation of Sichuan Agricultural University for Distinguished Young Teachers (Grant No. 007202)

摘　　要：Superparamagnetism amination nanocrystals Fe3O4 with 3-aminopropyltriethyloxy silane (APTES) were prepared by modified co-precipitation method. Next, 4―5 nm gold nanoparticles, prepared by classical Frens procedure, were coated on the surface of the amination Fe3O4 by self-assembly technology. The prepared Fe3O4@Au nanocomposite particles were investigated by transmission electron microscopy (TEM), UV-vis, infrared spectrum (FT-IR), and vibrating sample magnetometer (VSM) in order to eluci-date the morphology, optics and magnetic properties of the nanocomposites. Their uniform distribution of particle size,which is about 15 nm , and good magnetic responsiveness were observed. In view of the fact that Fe3O4 owns superparamagnetism and that nano-gold can readily combine with biological molecules, glucose oxidase (GOx) was chosen as a model to penetrate the condition of immobilizing enzyme, and enzymatic properties of resultant immobilized enzyme were studied as well. By systematic optimization, we established that at 28℃, and pH (5.5) and when mole ratio of Fe3O4:HAuCl4 was 0.5:1, the immobilization provided the best results. Finally, we are glad to find that the immobilized enzyme exhibits excellent thermostability in addition to its better stability than free enzyme. Thus, herein described immobilized enzyme could be used repeatedly with the assistance of an external magnetic field.Superparamagnetism amination nanocrystals Fe3O4 with 3-aminopropyltriethyloxy silane （APTES） were prepared by modified co-precipitation method. Next, 4-5 nm gold nanoparticles, prepared by classical Frens procedure, were coated on the surface of the amination Fe304 by self-assembly technology. The prepared Fe3O4@Au nanocomposite particles were investigated by transmission electron microscopy （TEM）, UV-vis, infrared spectrum （FT-IR）, and vibrating sample magnetometer （VSM） in order to eluci-date the morphology, optics and magnetic properties of the nanocomposites. Their uniform distribution of particle size, which is about 15 nm, and good magnetic responsiveness were observed. In view of the fact that Fe3O4 owns superparamagnetism and that nano-gold can readily combine with biological molecules, glucose oxidase （GOx） was chosen as a model to penetrate the condition of immobilizing enzyme, and enzymatic properties of resultant immobilized enzyme were studied as well. By systematic optimization, we established that at 28℃, and pH （5.5） and when mole ratio of Fe3O4：HAuCI4 was 0.5：1, the immobilization provided the best results. Finally, we are glad to find that the immobilized enzyme exhibits excellent thermostability in addition to its better stability than free enzyme. Thus, herein described immobilized enzyme could be used repeatedly with the assistance of an external magnetic field.

关 键 词：固定化葡萄糖氧化酶 纳米FE3O4 纳米复合材料 自组装技术 金纳米粒子 制备 FE3O4纳米粒子 振动样品磁强计 

分 类 号：Q554[生物学—生物化学] TB383[一般工业技术—材料科学与工程]