Citation: HE Mao-Fang, ZHANG Bo, TANG Yi-Mei, HAN Lu. Preparation of High Capacity Anion Exchange Magnetic Microspheres and Its Adsorption of Protein. Chinese Journal of Analytical Chemistry, 2018, 46(9): 1486-1492. doi: 10.11895/j.issn.0253-3820.181212 [复制]
Preparation of High Capacity Anion Exchange Magnetic Microspheres and Its Adsorption of Protein
为了获得高容量的阴离子交换吸附剂，本研究以Fe3O4磁性纳米粒子为基质，在其表面包覆聚多巴胺，然后与树枝状大分子聚乙烯亚胺反应，制得多氨基化磁性微球。此微球的离子交换容量为9.1 mmol/g。采用透射电镜、红外光谱和热重分析对材料进行了表征。以β-酪蛋白和牛血清蛋白（BSA）为模型蛋白，采用静态吸附法研究了此微球对蛋白质的吸附性能，在最佳条件下测定了微球对蛋白质的静态吸附等温线。结果表明，此微球对蛋白质的最佳吸附时间为2 h，缓冲溶液的最佳pH值为7.0。在此条件下，对β-酪蛋白和BSA的最大吸附容量分别为237.5和204.5 μg/mg，而对溶菌酶和核糖核酸酶A几乎不产生吸附。实验结果表明，此微球对酸性蛋白具有选择性，在蛋白质分离纯化方面具有良好的应用前景。
A high capacity anion exchange magnetic absorbent was prepared by immobilization of hyperbranched polyethyleneimine (PEI) on polydopamine-coated Fe3O4 microspheres (Fe3O4@pDA) and the ion exchange capacity was determined as 9.1 mmol/g. The absorbent was characterized by transmission electron microscope (TEM), infrared spectroscopy (IR) and thermogravimetric analysis (TGA). Moreover, the adsorption behavior of the absorbent for protein was carefully investigated by static adsorption using bovine serum albumin (BSA) and β-casein as models and then the static isotherms were determined under the optimum conditions. It was shown that the highest adsorption amount for protein was obtained when the adsorption time was 2 h and the pH was 7.0. Under the optimum conditions, the saturated adsorption capacity towards β-casein and BSA was determined as high as 237.5 and 204.5 μg/mg, respectively. Comparatively, the adsorbent exhibited little adsorption towards lysozyme and Rnase A, showing highly selectivity towards acidic protein. Therefore, the adsorbent exhibited potential in the separation and purification of protein from real samples.