Preparation Of Photoresponsive Molecularly Imprinted Materials Base On3,5-Dicarboxyazobenzene And Photo-controlled Extraction Of Purines

Purines are important alkaloids, because they widely participate in the life activities. Purine base damage or metabolic disorders would lead to a series of diseases, therefore, detecting purine has great significance. Molecularly imprinted polymers (MIPs) combine the advantages of structure-activity predetermination, specific recognition, and extensive practicability, we utilized molecular imprinting technique (MIT) to separate and detect purines. The photoresponsive MIPs were prepared using purines as the template, a new water-soluble photoresponsive azobenzene deravitive5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid (MAPDIA) as the functional monomer, and triethanolamine trimethacryl (TEAMA) as the cross-linker. The detailed research contents are described as follows:1. In Chapter One, the function and types of purine bases, the relationship between several important purine derivatives and diseases, the current research progress in purine compounds, and the defects of the current detection methods were firstly introduced. Secondly, the source and species of the MIT, the application of molecularly imprinted materials in solid phase extraction, and the research progress in photoresponsive MIT were reviewed. Finally, the purpose and significance of this study were raised.2. In Chapter Two, a water-soluble photoresponsive functional azobenzene monomer containing two carboxyl groups MAPDIA was prepared via diazotization coupling reaction and esterification reaction using commercially available5-aminoisophthalic acid, phenol, and methacrylic anhydride as the starting materials.’H NMR,13C NMR, and LC-MS were used to characterize their chemical structures, and UV-Vis was used to characterize their photoresponsive performance. A photoresponsive MIP was prepared with MAPDIA as the functional monomer, guanine as the template, and tetramethacryloyl triethylene tetramine (TTT), TEAMA or ethyleneglycol dimethacrylate (EGDMA) as the cross-linker. The MIP could efficiently extract guanine from beer and then release it in aqueous media upon photo-irradiation.3. In Chapter Three, on the surface of silica sphere, a surface molecularly imprinted polymer (SMIP) for the selective recognition of uric acid was prepared using MAPDIA as the functional monomer, TEAMA as the cross-linker, and uric acid as the template. The imprinting factor and selectivity factor of the potoresponsive SMIP was characterized via kinetic study, Scatchard analysis, specific recognition, and photocontrolled uptake and release. The morphology and structure were investigated by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), thermogravimetric (TG), fourier transform infrared spectroscopy (FT-IR), and N2-adsorption desorption analysis. The SMIP was applied for the solid-phase extraction of uric acid from urine with a96.0%recovery.4. In Chapter Four, on the surface of ZnO-nanorods, a ZnO-MIP for the selective recognition of uric acid was prepared using MAPDIA as the functional monomer, TEAMA as the cross-linker, and uric acid as the template. The SMIP displayed good photoresponsive properties in aqueous media. The imprinting efficiency and selectivity factor of the photoresponsive ZnO-MIP was characterized via kinetic study, Scatchard analysis, specific recognition, and photocontrolled uptake and release. The morphology and structure were investigated by HRTEM, TG, FT-IR, and N2-adsorption desorption analysis. The ZnO-MIP was applied for the solid-phase extraction of uric acid from urine and serum with recoveries of96.3%and95.7%, respectively.5. In the last chapter, the main results and conclusions were summarized, and some recommendations for future work are given...