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

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Fe304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（Polyallylamine magnetic nanogels，PAA，MNGs）。透射电子显微镜（Transmission electron microscope，TEM）和光子相关光谱（Photo correlation spectroscope，PCS）表征了PAA-MNG的形貌和粒径分布；热重分析（Thermogravimetric analysis，TGA）确定了磁性成分的含量，振动样品磁强计（Vibrating sample magnetometer，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，得到链亲和索包覆的纳米磁球（Streptavidin—coated magnetic nanoparticles，SA—MNPs）。使用探针生物素对硝基苯酯（Biotin P—nitrophenyl ester，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。

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

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 con- tent 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.