Shamim N, Hong L, Hidajat K, Uddin M S
Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
J Colloid Interface Sci. 2006 Dec 1;304(1):1-8. doi: 10.1016/j.jcis.2006.08.047. Epub 2006 Sep 28.
Adsorption and desorption behavior of Bovine Serum Albumin (BSA) on surface-modified magnetic nanoparticles covered with thermosensitive polymer (PNIPAM) was investigated as a function of temperature, pH, and ionic strength. Functionalization of surface-modified magnetic particles was performed by seed polymerization using N-isopropylacrylamide (PNIPAM) as the main monomer. Characterization of these particles was carried out using transmission electron micrography (TEM), and vibrating sample magnetometry (VSM). The adsorption results exhibited both pH and temperature sensitivity. The results showed that the temperature effect on adsorption/desorption behavior was mainly dependent on the properties of the particles' surface. The effect of pH was also investigated and it was observed that a smaller amount of protein was adsorbed at higher pH because of the electrostatic repulsive force between protein molecules and latex particles. The maximum amount of protein was adsorbed near the isoelectric point of BSA. Desorption results showed that more protein was desorbed when adsorption was done at lower temperatures and desorption efficiency was found to be higher than 80%.
研究了牛血清白蛋白(BSA)在覆盖有热敏聚合物(聚N-异丙基丙烯酰胺,PNIPAM)的表面改性磁性纳米颗粒上的吸附和解吸行为,该行为是温度、pH值和离子强度的函数。使用N-异丙基丙烯酰胺(PNIPAM)作为主要单体,通过种子聚合对表面改性磁性颗粒进行功能化。使用透射电子显微镜(TEM)和振动样品磁强计(VSM)对这些颗粒进行表征。吸附结果显示出对pH值和温度的敏感性。结果表明,温度对吸附/解吸行为的影响主要取决于颗粒表面的性质。还研究了pH值的影响,观察到在较高pH值下吸附的蛋白质量较少,这是由于蛋白质分子与乳胶颗粒之间的静电排斥力。在牛血清白蛋白的等电点附近吸附的蛋白质量最大。解吸结果表明,在较低温度下进行吸附时,更多的蛋白质被解吸,并且发现解吸效率高于80%。