Improvement of electrophoretic separation by surface functionalization of a capillary with nano-SiO2 and polyelectrolytes

Carboxyl modified magnetic nanoparticles coated open tubular column for capillary electrochromatographic separation of biomolecules

“…However, due to the limited amount of stationary phase coating, low phase ratio and sample capacity of OT columns are the primary drawbacks and restrict their widespread application in electrochromatographic separations. To overcome these shortcomings, a series of innovative approaches such as sol-gel derived phases [4,5], etching [6], porous layers [7,8] and nanoparticles (NPs) phases [9][10][11][12][13][14][15][16][17][18][19] have been developed to increase the inner surface area of columns and enhance the stationary/mobile phase interactions in OT-CEC separations. Among these approaches, NPs modified OT columns show a great promise to enhance the separation efficiencies of complex samples since NPs possess larger surface-to-volume ratio.…”

“…A semipermanent coating is based on the strong physical adsorption between coating material and the capillary wall, which can effectively avoid the loss of stationary phase [31]. Recently, poly(diallydimethylammonium chloride) (PDDA) has been widely used to fabricate semipermanent coating in OT-CEC via electrostatic attraction [10][11][12]14,15]. PDDA is a water-soluble cationic polyelectrolyte, which has a wealth of highly hydrophilic and positively charged quaternary ammonium groups.…”

“…PDDA is a water-soluble cationic polyelectrolyte, which has a wealth of highly hydrophilic and positively charged quaternary ammonium groups. Some NPs have been applied in OT-CEC as novel stationary phases by means of electrostatic self-assembly between PDDA and NPs, such as graphene [10], graphene oxide and reduced graphene oxide [11,12], nano-SiO 2 [14] and cyclodextrin-modified gold NPs [15].…”

“…For the past two decades, NPs with unique physical and chemical properties have made a significant contribution to the development of stationary phases in CEC, such as carbon NPs [9][10][11][12], silica NPs [13,14], metallic and metal-oxide NPs [15][16][17][18], and polymer NPs [1]. As one kind of extensively studied NPs, magnetic nanoparticles (MNPs) have received great attention for their superior characteristics such as good dispersion, excellent biocompatibility [20], high field irreversibility, ease of preparation, high ratio of surfaceto-volume [19] and remarkable physicochemical stability.…”

Applications of polydopamine modifications in capillary electrophoretic analysis

“…Therefore, various surface modification strategies have been introduced in CE to extend its practical uses, including chemical coating , dynamic coating , and physical coating . Among these approaches, physical coating is a widely used method for surface modification, such as coating with positively charged polymer , hydrophilic carboxymethyl chitosan , and nanosilica . Although diverse materials as physical coatings have been utilized in CE, the stability and fabrication complexity of the stationary phase are major obstacles hindering a broad range of applications.…”