Electrophoretic analysis of proteins and enantiomers using capillaries modified by a successive multiple ionic-polymer layer (SMIL) coating technique

Abstract

The applicability of three-layer coatings consisting of three different polymers (A(+)-B(-)-C(+) coating) prepared by a successive multiple ionic-polymer layer (SMIL) coating technique to the immobilization of polypeptides and/or proteins onto the inner surface of the capillaries was investigated to provide a high-performance separation medium for proteins and enantiomers in capillary electrophoresis (CE). To obtain a stable protein-coated capillary, high molecular mass poly(ethyleneimine) (PEI) was employed as the first layer in the A(+)-B(-)-C(+) coating, and then a cationic protein was immobilized as the third layer. Comparisons of analytical performances between the A(+)-B(-)-C(+) coating and the conventional SMIL-coated (A(+)-B(-)-A(+) coating) capillary were conducted. The CE separation of cationic proteins was successfully achieved with the prepared capillaries. In addition, the polypeptide- and protein-coated capillaries were applied to the chiral separation of a binaphthyl compound. It should be noted that the chiral separation efficiency was strongly dependent on the second anionic polymer layer of the coating. Effects of the interaction between oppositely charged ionic polymer layers on the separation efficiency are discussed.

Capillary electrophoresis of proteins 2005–2007

“…It comprised high-molecular-mass polyethyleneimine (PEI) as the bottom layer and a cationic protein as the upper layer [25].…”

Simple and Rapid Immobilization of Coating Polymers on Poly(dimethyl siloxane)-glass Hybrid Microchips by a Vacuum-drying Method

“…This may be caused by a less amount of the immobilized PEI onto the channel surface compared to previous polycations-coated columns. 26,27 An increased amount of immobilized PEI in the vacuum-dried coating would be attained by multiple deposition of PEI to obtain faster reversed-EOF. The run-to-run RSD of the EOF velocity in the PEI coating was estimated to be 4.9%, which was comparable to that of the DxS coated channel.…”

A novel PEG coating immobilized onto capillary through polydopamine coating for separation of proteins in CE

“…CE has been proven to be an important tool for the analysis of a wide variety of biomolecules such as proteins and DNA [1,2]. The advantages of CE include high separation efficiency, short analysis time, and low sample consumption [3,4].…”