Wang Wei, Jing Ying, He Shihai, Wang Jian-Ping, Zhai Jian-Ping
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China.
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Colloids Surf B Biointerfaces. 2014 May 1;117:449-56. doi: 10.1016/j.colsurfb.2013.11.050. Epub 2013 Dec 12.
Magnetic Fe70Co30 nanoparticles with a cubic shape and a mean size of 15±1.5 nm were fabricated using a magnetron-sputtering-based gas phase condensation deposition method. The particles had a high saturation magnetization of 220 emu/g, which is much higher than that of commercially available iron oxide nanoparticles. The FeCo nanoparticles were modified by 3-aminopropyltriethoxy silane and subsequently activated by glutaraldehyde, leading to successful attachment of aldehyde groups onto nanoparticle surfaces. Three proteins, namely streptavidin, PAPP-A antibody and Nectin-4 antibody, were immobilized on glutaraldehyde activated FeCo nanoparticles, and their loading levels were quantitatively evaluated. Our results show that loading capabilities are 95 μg of streptavidin, 128 μg of PAPP-A, and 125 μg of Nectin-4 antibody per milligram of FeCo nanoparticles, and that the three immobilized proteins retain their binding bioactivity. The protein-FeCo conjugates may find valuable applications involving magnetic separation and purification of proteins and cells, and the magnetic detection of biomolecules.
采用基于磁控溅射的气相冷凝沉积法制备了立方形状、平均尺寸为15±1.5 nm的磁性Fe70Co30纳米颗粒。这些颗粒具有220 emu/g的高饱和磁化强度，远高于市售的氧化铁纳米颗粒。FeCo纳米颗粒用3-氨丙基三乙氧基硅烷进行修饰，随后用戊二醛活化，从而使醛基成功附着在纳米颗粒表面。将三种蛋白质，即链霉亲和素、妊娠相关血浆蛋白A（PAPP-A）抗体和Nectin-4抗体固定在戊二醛活化的FeCo纳米颗粒上，并对它们的负载水平进行了定量评估。我们的结果表明，每毫克FeCo纳米颗粒的负载能力分别为95 μg链霉亲和素、128 μg PAPP-A和125 μg Nectin-4抗体，并且三种固定化蛋白质保留了它们的结合生物活性。蛋白质-FeCo缀合物可能在涉及蛋白质和细胞的磁分离与纯化以及生物分子的磁性检测等方面找到有价值的应用。
