Wang Yujun, Wang Xianghua, Luo Guangsheng, Dai Youyuan
State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, PR China.
Bioresour Technol. 2008 Jun;99(9):3881-4. doi: 10.1016/j.biortech.2007.08.017. Epub 2007 Sep 24.
The adsorption characteristics of BSA onto the magnetic chitosan nanoparticles have been investigated in this paper. The magnetic chitosan nanoparticles were prepared by adding the basic precipitant of NaOH solution into a W/O microemulsion system. The morphology of magnetic chitosan nanoparticles was observed by transmission electron microscope (TEM). It was found that the diameter of magnetic chitosan nanoparticles was from 10nm to 20 nm, and the nanoparticles suspending in the aqueous solution could easily aggregate by a magnet, which suggested that the nanoparticles had good magnetic characteristics. The BSA adsorption experiment indicated that when pH of BSA solution was equal to 4, the maximum adsorption loading reached 110 mg/g. Through measuring the zeta potential of BSA solution and the magnetic nanoparticles, it was found that under this situation the surface of BSA took the negative charge, but the magnetic nanoparticles took the positive charge. Due to the small diameter, the adsorption equilibrium of BSA onto the nanoparticles reached very quickly within 10 min. The adsorption equilibrium of BSA onto the magnetic chitosan nanoparticles fitted well with the Freundlich model. The experimental results showed that the magnetic chitosan nanoparticles have potential to be used for the quick pretreatment in the protein analysis process.
本文研究了牛血清白蛋白（BSA）在磁性壳聚糖纳米粒子上的吸附特性。通过向W/O微乳液体系中加入NaOH溶液碱性沉淀剂制备磁性壳聚糖纳米粒子。用透射电子显微镜（TEM）观察磁性壳聚糖纳米粒子的形态。发现磁性壳聚糖纳米粒子的直径为10nm至20nm，悬浮在水溶液中的纳米粒子可以很容易地被磁铁聚集，这表明纳米粒子具有良好的磁性。BSA吸附实验表明，当BSA溶液的pH值等于4时，最大吸附量达到110mg/g。通过测量BSA溶液和磁性纳米粒子的zeta电位，发现在这种情况下BSA表面带负电荷，而磁性纳米粒子带正电荷。由于直径小，BSA在纳米粒子上的吸附平衡在10分钟内很快达到。BSA在磁性壳聚糖纳米粒子上的吸附平衡与Freundlich模型拟合良好。实验结果表明，磁性壳聚糖纳米粒子在蛋白质分析过程中具有用于快速预处理的潜力。
