基底表面浸润性对磁性载体/蛋白纳米复合物吸附的影响

Effect of Substrate Surface Wettability on the Adsorption of Magnetic Carrier/Protein Nanocomposites

在玻璃基底上分别生长了疏水的ZnO晶种层和超疏水的ZnO纳米线阵列.在磁场作用下1 min内,磁性载体/牛血清白蛋白纳米复合物在基底表面即可达到吸附饱和值;同时发现,以ZnO纳米线阵列为分离基底时的磁分离效率明显高于玻璃片和ZnO晶种层,且这种差距随着纳米复合物浓度的降低而加大,这与超疏水基底具有较小的固-液接触面积及较大的流体剪切力有关.进一步将目标蛋白拓展至血红蛋白及溶菌酶这2种具有不同性质的典型蛋白,证实了该影响规律具有一定的普适性,超疏水基底在提高蛋白磁分离效率方面比商用玻璃、聚丙烯塑料和疏水基底具有更明显的优势,并对"硬"蛋白具有更佳的磁分离效果.本研究有助于进一步理解界面性质对蛋白吸附行为的影响,并为构建新型高效蛋白分离平台开辟了新思路.

Hydrophobic ZnO seed layer and superhydrophobic ZnO nanowire array were grown on glass substrate,respectively. The adsorption of the magnetic carrier/bovine serum albumin（ BSA） nanocomposites could reach a maximum saturation level upon applying an external magnetic field. The magnetic separation efficiencies using the ZnO nanowire array as the separation substrate were proved to be much higher than those using glass or the ZnO seed layer as the separation substrate. And the difference became large with the decrease of the nanocomposite concentrations. It might be attributed to the small solid-liquid contact area of the superhydrophobic substrate and its strong flow shear. The target protein was then further expanded to the other two typical proteins with different properties,i. e.,hemoglobin and lysozyme. And the results proved that the effect rule of the substrate surface wettability on protein adsorption was universal. The superhydrophobic substrate has a more obvious advantage in improving the magnetic separation efficiency than commercial glass,polypropy-lene and hydrophobic substrate,and exhibited outstanding magnetic separation efficiencies for＂hard＂proteins. The present work could contribute to a better understanding of the effect of the interfacial property on protein adsorption behavior,and open up a new avenue to fabricate highly efficient protein separation platform.