DOI: 10.3724/SP.J.1249.2015.01076
采用共沉淀法制备核层为四氧化三铁(Fe3O4)壳层为聚乙烯亚胺(polyethyleneimine, PEI)的磁性复合纳米粒子Fe3O4-PEI.扫描电子显微镜和透射电子显微镜表征结果显示,制备的磁性复合纳米粒子Fe3O4-PEI粒径均匀,直径约为25 nm. 通过振动样品磁强计比较Fe3O4-PEI和Fe3O4纳米粒子的磁滞回线,结果表明,经PEI包覆后复合纳米粒子饱和磁化值为38.2 emu/g,仍具有较好的磁性. 热重分析表明,包覆在Fe3O4纳米粒子表面的PEI质量分数约为23.26%.通过静电作用,实现了Fe3O4-PEI复合纳米粒子对葡萄糖氧化酶的负载,以铂电极为基底电极,制备了Fe3O4-PEI-GOx/Pt葡萄糖传感器. 在最优测试条件下,该修饰电极对葡萄糖表现出优异的电化学催化性能,具有灵敏度高、抗干扰能力强、稳定性好的特点.
Fe3O4-PEI nanoparticles with Fe3O4 core and polyethylenimine(PEI)shell were prepared via the co-precipitation method. Results from scanning electron microscope(SEM)and transmission electron microscope(TEM)show that Fe3O4-PEI nanoparticles present globular shape with almost uniform diameters of about 25 nm. Magnetic hysteresis loops of Fe3O4-PEI and Fe3O4 nanoparticles were obtained by a vibrating sample magnetometer(VSM). The magnetism of Fe3O4 nanoparticles still remains a lot after coating with PEI, and the saturation magnetization value of Fe3O4-PEI nanoparticles is 38.2 emu/g. Thermogravimetry(TG)analysis indicats that the loading amount of PEI on the surface of Fe3O4 nanoparticles is about 23.26%. The glucose oxidase(GOx)enzyme was immobilized on the Fe3O4-PEI nanoparticles surface by electrostatic interaction. Fe3O4-PEI-GOx/Pt glucose sensor was prepared with platinum(Pt)as its basal electrode, which exhibits a good electrochemical catalysis for glucose, high sensitivity, strong anti-interference ability and long-term durability for glucose detection under an optimal preparation condition.
