Preparation And Properties Of Macromolecularly Surface-imprinted Alginate-based Hybrid Polymer Microspheres

In recent years molecular imprinting polymer (MIP) and molecular imprinting technology (MIT) has received a great deal of attention, which exhibited an extensive application in industrialization fields and in academe. In this thesis, the principle of MIT, the preparation methods of molecularly imprinted polymeric microspheres (MIPMs), and the application of MIPMs, as well as the specialty and methods of protein surface imprinting was expatiated detailedly. The preparation and properties of macromolecularly imprinted alginate-based hybrid polymer microspheres were researched.Firstly, calcium phosphate/alginate(CP/A), calcium polyacrylate/alginate(CPA/A) and calcium phosphate/polyacrylate/alginate(CP/PA/A) macromolecularly imprinted hybrid polymer microspheres were firstly designed and prepared with sodium alginate (SA) and sodium polyacrylate (SPA) by using CaCl2 as gelling agent in inverse-phase suspension. Morphology of BSA imprinted alginate-based hybrid polymer microspheres was observed by optical microscopy and scanning electron microscope (SEM). Infrared spectrum and conductance titration analysis demonstrated that hybrid components were produced in these microspheres. It was found that these calcium alginate based hybrid microspheres exhibited pH and ion-sensitive swelling properties.Based on this investigation, protein surface imprinted (compared to embedding imprinted) hybrid microspheres were prepared, which had different specific rebinding properties. Preparation process and characters of imprinted microspheres, such as the ingredient, the concentration of CaCl2, template content and pH etc. were analyzed to explore approaches for higher imprinting efficiency. Rebinding dynamic and thermodynamic behaviors of the two imprinted microspheres were evaluated, resulting in a higher affinity for imprinted microspheres relative to non-imprinted ones. Selectivity tests showed that the imprinted beads exhibited good recognition properties for the template protein. It was found that SMIPMs exhibited higher rebinding rate and better the specific rebinding property than EMIPMs did.It is found that many factors in gelling, removing template and rebinding process such as pH values and ionic concentration etc. make an important influence on the parameters such as rebinding capacity and imprinting efficiency etc. of protein-imprinted hybrid microspheres. Furthermore, the principle of target interaction model between protein and imprinting substrate in the level of molecular structure were used to investgate the optimized environmental conditions and the specific rebinding properties corresponding to the process of gelling, removing template and rebinding. The optimized pH values for the imprinting of BSA in gelling, removing template and rebinding procedure was 4.0-4.2, 8.14-8.42 and 4.7-4.9, respectively.