Zhang Yao-Yao, Xu Wang, Cao Jian-Fang, Shu Yang, Wang Jian-Hua
Department of Chemistry, College of Sciences, Northeastern University, Shenyang, 110819, China.
Department of Chemistry, College of Sciences, Northeastern University, Shenyang, 110819, China.
Anal Chim Acta. 2021 Feb 22;1147:144-154. doi: 10.1016/j.aca.2020.12.046. Epub 2021 Jan 1.
Zr-based metal-organic framework, UiO-66-NH, provides favorable adsorption capacity to phosphoproteins, however, it exhibits obvious nonspecific adsorption to other proteins. In the present work, we report a facile strategy to reduce the nonspecific adsorption of nonphosphoproteins by modifying UiO-66-NH with imidazolium ionic liquids (ILs). With respect to bare UiO-66-NH, the modified counterpart, UiO@IL, exhibits much improved selectivity to phosphoproteins while maintains comparable adsorption performance. The surface of UiO@IL presents a strong hydrophilicity due to the modification of ILs. Hydrophobic and electrostatic interaction between the absorbent and nonphosphoprotein is significantly reduced. In addition, the interaction between imidazole group of ILs moiety and phosphate group in phosphoprotein ensures the favorable adsorption capacity of UiO@IL for phosphoproteins. Anionic moieties of ILs, i.e., Cl, Br, BF, CFSO, play negligible effect in the adsorption process. As a representative, phosphoprotein β-casein (β-ca) is selectively enriched at a mass ratio of BSA:β-ca = 100:1. UiO@IL was further applied for the selective enrichment of phosphoprotein in milk.
基于锆的金属有机框架材料UiO-66-NH对磷蛋白具有良好的吸附能力，然而，它对其他蛋白质表现出明显的非特异性吸附。在本工作中，我们报道了一种通过用咪唑鎓离子液体（ILs）修饰UiO-66-NH来降低非磷蛋白非特异性吸附的简便策略。相对于未修饰的UiO-66-NH，修饰后的材料UiO@IL对磷蛋白的选择性有了显著提高，同时保持了相当的吸附性能。由于ILs的修饰，UiO@IL的表面呈现出很强的亲水性。吸附剂与非磷蛋白之间的疏水作用和静电作用显著降低。此外，ILs部分的咪唑基团与磷蛋白中的磷酸基团之间的相互作用确保了UiO@IL对磷蛋白具有良好的吸附能力。ILs的阴离子部分，即Cl、Br、BF、CFSO，在吸附过程中起的作用可忽略不计。作为一个代表性例子，在牛血清白蛋白（BSA）与β-酪蛋白（β-ca）质量比为100:1时，磷蛋白β-酪蛋白被选择性富集。UiO@IL进一步应用于牛奶中磷蛋白的选择性富集。
