光化学制备用于链亲和素固定的胺基磁性纳米凝胶的研究

Photochemical preparation of amino-functionalized magnetic nanogels for immobilization of streptavidin

本工作提出制备胺基磁性纳米凝胶的一种改进方法。在含有烯丙基胺的Fe3O4水分散液中,运用紫外光辐照引发烯丙基胺原位聚合,一步法制备了聚烯丙基胺磁性纳米凝胶(Polyallylaminemagneticnanogels,PAA-MNGs)。透射电子显微镜(Transmissionelectronmicroscope,TEM)和光子相关光谱(Photocorrelationspectroscope,PCS)表征了PAA-MNG的形貌和粒径分布;热重分析(Thermogravimetricanalysis,TGA)确定了磁性成分的含量,振动样品磁强计(Vibratingsamplemagnetometer,VSM)测试表明其呈现超顺磁性。利用表面的伯胺基,PAA-MNGs可以方便地偶联蛋白等生物大分子。链亲和素(Streptavidin,SA)经1-乙基3-(3-二甲氨基)碳化二亚胺盐酸盐和N-羟基琥珀酰亚胺活化后可以共价固定在PAA-MNGs上,得到链亲和素包覆的纳米磁球(Streptavidin-coatedmagneticnanoparticles,SA-MNPs)。使用探针生物素对硝基苯酯(Biotinp-nitrophenylester,BNPE)通过光谱检测证实了SA-MNPs的生物素结合能力。表明PAA-MNGs适合于作为载体偶联蛋白等生物大分子,并可能用于生物技术领域的诸多方面。

An improved approach for preparing amino-modified magnetic nanogels has been developed in this paper. Polyallylamine magnetic nanogels （PAA-MNGs） were synthesized in one step by photoinitiation and in situ photopolymerization of allylamine in Fe3O4 aqueous suspension under UV irradiation. Morphology, mean diameter and diameter distribution of the PAA-MNGs were measured by TEM and PCS respectively, while the magnetite content was confirmed by TG and the superparamagnetism identified by VSM. Biomolecules, such as proteins, can be coupled to the surface of PAA-MNGs in virtue of amino groups. Streptavidin-coated magnetic nanoparticles （SA-MNPs） were prepared by covalent immobilization of streptavidin （SA） activated by 1-Ethyl-3- （3-dimethyl- laminopropyl） carbodiimide hydrochloride （EDC） and N-hydroxysuccinimid （NHS） on PAA-MNGs. The biotin binding capacity of SA-MNPs was proved by colorimetric measurements using the probe biotin p-nitrophenyl ester （BNPE）. Therefore, PAA-MNGs may be a suitable vehicle to carry biomolecules for applications in many areas of biotechnology.