Studying the interaction between peptides and polymeric nanoparticles used as pseudostationary phase in capillary electrochromatography

In this work, the interaction between synthetic bioactive peptides and polymeric nanoparticles (NPs) used as pseudostationary phase in capillary electrochromatography was studied. NPs were prepared from methacrylic acid and ethylenglycol dimethacrylate with benzoyl peroxide by utilizing a precipitation polymerization technique. The reaction was monitored by infrared spectroscopy. Polymer characterization was performed by dynamic light scattering and transmission electron microscopy. Experimental running conditions were tested, including organic solvent proportion in the background electrolyte, capillary conditioning, applied voltage, sample introduction amount, and how NPs were incorporated into the system. A continuous full filling technique in which the NPs were suspended in the entire electrolyte volume as well as a conventional partial filling technique were used. Results obtained at pH 7.0 suggest that the NPs have a very strong interaction with more basic peptides. The interaction between analytes and NPs was found to be predominantly ionic.