Adsorption myoglobin over mesoporous silica molecular sieves: Pore size effect and pore-filling model

The present work describes the adsorption of myoglobin over mesoporous materials with different pore diameters (SBA-15 and MCM-41) from buffered solutions. The Langmuir-type adsorption of myoglobin occurs with monolayer coverage on the inner surface of the mesoporous channels. These adsorbents were thoroughly characterized by X-ray diffraction, nitrogen adsorption/desorption and FT-IR spectroscopy before and after the myoglobin adsorption. The amount of myoglobin adsorbed significantly depends on the specific pore volume and/or the pore diameter of the mesoporous silica adsorbents. These experimental results were analyzed using pore-filling models, suggesting that myoglobin molecules are well-packed in the SBA-15 pores. FT-IR spectra before and after the adsorption confirm the structural stability of the adsorbed myoglobin.