α-胰凝乳蛋白酶在相转移Fe_3O_4纳米粒子表面的固定化

α-Chymotrypsin Immobilization on the Surface of Phase-transferred Fe_3O_4 Nanoparticles

采用高温热分解前驱体乙酰丙酮铁法合成了尺寸均一且分散性好的油溶性Fe3O4纳米粒子,通过表面配体置换直接将其表面换为水溶性分子聚乙二醇二酸(PEG diacid),形成了具有表面功能基的稳定无毒的水溶性磁性复合体系.TEM,M-H曲线,FTIR和TGA等表征结果表明,油溶性Fe3O4纳米粒子已成功转移至水相,且具有很好的顺磁性及生物相容性.研究结果表明,α-胰凝乳蛋白酶(α-ChT)被成功地固载到水溶性Fe3O4纳米粒子表面,与自由酶相比,固定化酶的热稳定性明显提高,并体现出良好的可重复利用性.

The oil-soluble magnetic Fe304 nanopartieles with uniform size and morphology were synthesized t;ia thermal decomposition of Fe （acac）3 precursor. They were successfully transferred into aqueous phase through the ligand-exehange reaction with water-soluble PEG diacid molecule, forming water-soluble, stable, nontoxic, and magnelic composite with surface functional group. TEM, M-H curve, FTIR and TGA were used to characterize the as-synthesized composite and demonstrated that the nanoparticles maintained their superparamagnetism and biocompatibility, α-Chymotrypsin（α-ChT） was immobilized on the surface of the watersoluble nanoparticles. The immobilized α-ChT exhibited better thermal stability and high activity after repeated usage.