Ionic liquid modification of metal-organic framework endows high selectivity for phosphoproteins adsorption.

Yao-Yao Zhang, Wang Xu, Jian-Fang Cao, Yang Shu, Jian-Hua Wang

Analytica chimica acta 2021 Feb 22

filter terms:

Zr-based metal-organic framework, UiO-66-NH2, 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-NH2 with imidazolium ionic liquids (ILs). With respect to bare UiO-66-NH2, 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-, BF4-, CF3SO3-, 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. Copyright © 2021 Elsevier B.V. All rights reserved.

Citation

Yao-Yao Zhang, Wang Xu, Jian-Fang Cao, Yang Shu, Jian-Hua Wang. Ionic liquid modification of metal-organic framework endows high selectivity for phosphoproteins adsorption. Analytica chimica acta. 2021 Feb 22;1147:144-154