纳米 SiO2亲和吸附剂的制备及性能

摘要

采用水热法一步合成了巯基纳米二氧化硅(SiO 2-SH),随后在其表面修饰亚氨基二乙酸基团(-IDA)得到了 SiO 2-SH/IDA,利用-SH 和-IDA 双官能团更多的吸附溶液中的 Ni2+,从而得到 SiO 2-SH/IDA-Ni2+纳米亲和吸附剂.制备的亲和吸附剂可直接用于六聚组氨酸为标签的(His-tagged)融合蛋白的分离纯化.利用 TEM、FT-IR、TG、SDS-PAGE 等大型仪器表征了样品的形貌、结构及亲和分离能力.结果表明制备的 SiO 2-SH/IDA-Ni2+纳米亲和吸附剂平均粒径为60 nm,对 His-tagged蛋白具有较好的特异性和较低的检测限(约为1.9×10-5 mol/L),且该吸附剂再生能力较强,再生3次后对目标蛋白仍具有较好的分离效果.%Silica nanospheres (NSs)with thiol group (SiO 2-SH)were synthesized by the hydro-thermal method.Then the iminodiacetic acid group (-IDA)was modified on the surface of SiO 2-SH to obtain SiO 2-SH/IDA NSs.Subsequently the Ni2 + ions in the solution were ad-sorbed by both -SH group and-IDA group of SiO 2-SH/IDA NSs,which could adsorb more Ni2 + on the surface of these NSs to get SiO 2-SH/IDA-Ni2 + adsorbent.Then the adsorbent was used to separate His-tagged proteins.The morphology,composition and affinity separation properties were detected by TEM,FT-IR,TG and SDS-PAGE.The results show that the av-erage size of the prepared SiO 2-SH/IDA-Ni2 + adsorbent is about 60 nm,which can separate the His-tagged protein specificly and has lower detection limit (1.9 × 10 -5 mol/L)and the better regeneration ability after three times reuse.