Protein Adsorption on Inorganic Zeolite Materials

This study sought to examine the adsorption characteristics of bovine serum albumin (BSA) and cytochrome c (cyt c) on zeolite crystals and membranes. The zeolite materials were prepared by hydrothermal syntheses using different reaction gels to modulate the Brönsted acidity of the microporous structures. In addition, to modulate the surface acidity of the MFI structure, aluminium and vanadium atoms were incorporated into the crystalline framework and the ratios of Si/Al, Si/V, and Al/V were varied changing the chemical composition of the precursor reaction gels. Protein adsorption was studied under different conditions using spectroscopic techniques such as UV-visible and attenuated total reflectance Fourier transform infrared (FT-IR/ATR). This study revealed that zeolite chemical composition and structure influence the kinetics of protein adsorption. The surface of zeolite Na-Y adsorbed a greater amount of BSA and cyt c than the other structures. The percentage of adsorption of BSA depended on the pH of the solution, with adsorption greatest when the pH was near the pI of the protein. The influence of the membrane configuration on the protein adsorption was studied using different zeolite structures and crystallization types. The results suggest that the differences in adsorption capacity depend on the type of hydrothermal crystallization inside the inorganic support.