Surfactant-based coatings for protein separation by capillary electrophoresis - A review

Capillary electrophoresis (CE) is a highly efficient and versatile analytical method for the separation of biomacromolecules such as proteins and peptides. One major concern to reach high separation efficiency is the adsorption of analytes on the capillary wall and the heterogeneity of the capillary surface charge which generates hydrodynamic dispersion due to local electroosmotic (EOF) fluctuations.

Double chain surfactants have been described as potential interesting candidates for capillary coatings in CE. They are notably offering a very homogenous surface charge leading to very high separation efficiency with reported values up to 1 million plates per meter.

This review provides an overview of double chain surfactant coatings used in CE with an emphasis on the coating protocol, the nature of the surfactant, the preparation of the coating solution (concentration, temperature, sonication or extrusion), the physicochemical parameters affecting their properties (pH, ionic strength, nature of the anion in the coating solution, coating additives, capillary internal diameter), and the coating stability/durability.