title: The coating of smart pH-responsive polyelectrolyte brushes in capillary and its application in CE.
abstract: A novel pH-responsive coating technique was developed and applied to CE successfully in this paper. The coating was formed by bonding mixed opposite charge poly(acrylic acid) and poly(2-vinylpyridine) randomly onto the inner wall of a silica capillary. The coating processes were first characterized by ellipsometry and atomic force microscopy at macroscale and microscale, respectively. Measurements of EOF were implemented to confirm the coating. Direction and velocity of EOF became controllable from negative to positive, showing a perfect sigmoidal curve as the coating net charges alternated by the pH of BGE. The control of the EOF makes it possible to analyze different kinds of small molecules, peptides, and proteins successfully in the same capillary. Results showed that the stability and reproducibility for separations of fluoroquinolone standards were satisfactory for more than a hundred separations. A series of basic and acidic protein standards were separated with admirable efficiency and minimal adsorption using both polarities. The separation of tryptic BSA digest showed that the prepared capillary has immense potential in analyzing a single sample with both acidic and basic separations, which achieved the expectation in proteomics study by CE-MS.
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry, Peking University, Beijing, PR China.
authors: Jing-Xin
authors: JX
authors: Liu
authors: Ming-Zhe
authors: MZ
authors: Zhao
authors: Yan
authors: Y
authors: Deng
authors: Cai
authors: C
authors: Tie
authors: Hong-Xu
authors: HX
authors: Chen
authors: Ying-Lin
authors: YL
authors: Zhou
authors: Xin-Xiang
authors: XX
authors: Zhang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002645:Chickens; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D011145:Polyvinyls / Q000737:chemistry*; D011506:Proteins / Q000302:isolation & purification*; D015203:Reproducibility of Results
chemical_list: D000180:Acrylic Resins; D011145:Polyvinyls; D011506:Proteins; C058671:poly(2-vinylpyridine); C006903:carbopol 940