| Due to the special physical and chemical properties, the nanometer materials is in the rapid development of biology and medicine research, such as drug delivery, imaging, treatment, diagnosis, and then further development, including the activation/deactivation, generic, and realize the functions of the system of biological molecules, and also widely used in enzyme, peptides and nucleic acid adsorption carrier. High specific surface area of SiO2 is a non-toxic, tasteless, no pollution of non-metallic materials, which has many characteristics, such as low density, cellular density porous, an ideal choice adsorbent.The mesoporous silica particles with different specific surface area were synthesized by using cationic surfactant three alkyl sixteen methyl bromide (CTAB) as the template. The crystal morphology and other physical and chemical properties of the mesoporous silica nanoparticles were characterized by scanning electron microscopy (SEM), X ray diffraction (XRD), Fourier transition infrared spectroscopy (FTIR) and specific surface area analysis. The results shows that the surface area of mesoporous silica are changed with the increase of CTAB content. When the CTAB addition amount is 0.95g, the silica has a typical two-dimensional hexagonal mesostructure,the specific surface area is up to 1098.392m2/g.At the same time,the morphology has also gradually neat, from random shape into a hexagonal bar structure, the channel order to achieve the best. When CTAB add quantity more than 0.95 g, morphology regularity and channel order decreases, and the specific surface area is reduced at the same time.In the process of experiment, through the single factor control variable method, change the condition factors in the process of adsorption of BSA by the nano SiO2, to find out the best conditions of adsorption reaction. Results show that he most suitable conditions for the adsorption are as follows, the pH value in the adsorption system is 5, adsorption time is 250 min, BSA initial amount is 1.2 mg/mL and 30℃ reaction temperature. Respectively by Langmuir adsorption isotherm model and Freundlich adsorption isotherm model for experimental adsorption data fitting, the adsorption of BSA by the nanometer SiO2 model belongs to Freundlich adsorption isotherm models, and the reaction is easy to happen. Through pseudo first-order kinetics and pseudo secondary kinetic equation of adsorption data fitting calculation, learned that nanometer SiO2 adsorption of BSA adsorption experimental data in line with the pseudo first-order kinetics equation.The equation shows that the process of the adsorption of BSA by nano-SiO2 belongs to molecular levels, sites of combination of adsorption.Mainly controlled by the mass transport in the process of adsorption steps and physical factors such as experimental conditions, and not affected by chemical factors.However, numerous studies have shown that nano material itself has a potential toxicity, and when the nanometer materials and protein combination happens, a variety of adverse side effects, such as particle aggregation, nonspecific adsorption, signal protein produced or unknown epitope exposed, are likely to cause biological function disorder and unknown physiological effect. Therefore, to choose the right means of characterization analysis of the various features of protein corona is extremely important.Using scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TG) and fluorescence spectrum analysis method, to characterize the type of silica nanoparticles morphology and change of the physical and chemical properties.The results showed that the morphology and size changes obviously after the BSA adsorption by the nano SiO2.The (110), (200) diffraction peak of SiO2 particles has disappeared, skeleton ordered degree is reduced. The thermodynamic data analysis shows that delta AH0<0,AG0<0, reflect that SiO2 with BSA interaction process is spontaneous and exothermic.Infrared spectrum and fluorescence spectrum showed that after the adsorption by the nano SiO2 particles, the stability of the alpha helix of BSA is relatively lower, the content of beta folding decreased, and the mainly force between SiO2 and BSA is electrostatic interactions. |
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