Selective Separation and Adsorption of Bovine Serum Albumin and Ovalbumin by Magnetic Solid-Phase Extraction (MSPE) Using Poly(Diallyldimethylammonium Chloride) Modified Cobalt Ferrite Filled Multiwalled Carbon Nanotubes as the Adsorbent

Abstract

A novel poly(diallyldimethylammonium chloride) (PDDA) surface modified magnetic cobalt ferrite-filled multiwalled carbon nanotubes (CoFe₂O₄@MWCNTs-PDDA) composite is reported. The CoFe₂O₄@MWCNTs-PDDA was characterized by transmission electron microscopy, fourier transform infrared spectrometry, x-ray diffraction, and vibrating sample magnetometry and used for the selective adsorption of acidic proteins. The presence of MWCNTs served as a protective layer, which improved the stability of the magnetic composite, and also enlarged the surface area from 67 m²·g⁻¹ to 186 m²·g⁻¹, which provided a substrate with larger specific surface area for PDDA wrapping and enhanced the selectivity and adsorption capacity for acidic proteins. The adsorption capacity of CoFe₂O₄@MWCNTs-PDDA was 378.1 mg·g⁻¹ for bovine serum albumin and 363.4 mg·g⁻¹ for ovalbumin, an increase of approximately 20-fold, 3-fold, and 4-fold compared to CoFe₂O₄, CoFe₂O₄@PDDA and CoFe₂O₄@MWCNTs, respectively. The practical application of the CoFe₂O₄@MWCNTs-PDDA was demonstrated by processing whole blood samples for the extraction of acidic proteins. Satisfactory results were obtained by sodium dodecyl sulfate–polyacrylamide gel electrophoresis.

KEYWORD:

• Bovine serum albumin
• cobalt ferrite filled multiwalled carbon nanotube
• magnetic solid-phase extraction
• ovalbumin
• poly(diallyldimethylammonium chloride)

Disclosure statement

The authors declare that they have no known competing financial interests that influenced the work reported in this article.

Ethical approval

All experiments involving human subjects were approved by the Committee for the Protection of Human Subjects at the First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine.

Additional information

Funding

We greatly appreciate the support of the National Natural Science Foundation of China (81960787), the Natural Science Foundation of Guizhou Province of China ([2020] 1Y041), Guizhou Youth Science and Technology Talents ([2018] 293), and Guizhou Provincial Science and Technology Projects (ZK [2022] key 004).