Preparation Of Novel Surface Imprinted Polymers And Their Applications In Sample Pretreatment And Sensors

Sample pretreatment techniques have still played important and irreplaceable roles in the environmental pollutants analysis. As for the high sensitive instrument, it requires high purity of the sample. Molecular imprinting technology due to its good selectivity has been rapidly developed in sample pretreatment, sensing, enzymes simulation. MIPs still face severe challenges, involving low binding capacity, template leakage and slow transfer rate. In the present thesis, some new technologies and materials were introduced to combine with surface molecular imprinting and a series of surface imprinting polymers were developed and applied to the environment and biological samples, and the research contents and results are as follows:(1) Uniform core-shell molecularly imprinted polymers: A correlation study between shell thickness and binding capacityHerein, we purpose to explore the correlation between shell thickness and binding capacity to prepare different CS-MIPs at the surface of carboxyl polystyrene through emulsion polymerization. Main factors were studied such as the amount of prepolymer solution, the amount of SDS and the temperature step. Consequently, the CS-MIPs with 2.60 μm of shell thickness presented the highest binding capacity of 30.1μmol/g and the most rapid mass transfer rate. The static adsorption isotherm followed the Langmuir-Freundlich adsorption model, and the kinetics obeyed the pseudo-second-order kinetics model. Recognition specificity for Sudan I with respect to its analogues was well displayed, with a high imprinting factor of 2.69. The establishment of critical value of shell thickness provides new insights into the preparation methodology and molecular recognition mechanism of core-shell imprinted polymers.(2) Magnetic coreshell imprinting microspheres strategy for recognition and detection of phycocyaninBy using phycocyanin as a model, we developed a facile and highly efficient approach to obtain magnetic coreshell imprinting microspheres. Miniemulsion polymerization was employed, based on surface immobilization of phycocyanin with IV aminolysis and aldehyde modification on magnetic support particles. The imprinting microspheres exhibited high adsorption capacity of 10.53 mg/g, excellent binding selectivity toward phycocyanin with a high imprinting factor of 2.41. Furthermore, fast magnetic separation and sensitive fluorescent detection in a wide p H range was offered for phycocyanin. Consequently, the imprinting microspheres were successfully as sorbents applied for selective isolation of phycocyanin from protein mixtures. Taking advantages of magnetic polymers and surface imprinting, the developed strategy provides great application potentials for convenient, rapid targeting identification/enrichment and separation of proteins.(3) Magnetic molecularly imprinted micromotor for selective recognition and transport of fluorescent phycocyanin in seawaterAn attractive magnetic micromotor for selective recognition and transport of phycocyanin via a template electrodeposition process was proposed. The MIP-based catalytic micromotor was fabricated using phycocyanin as imprinting molecule, PEDOT as electrochemical selective material, nickel as magnetic navigation material, and metal platinum as solid support and catalyst to facilitate the catalytic micromotor freely move in solutions. The autonomous self-propulsion micromotor presented two different trajectories by confocal microscope. The movement velocity was calculated based on the body-deformation model, suggesting a linear positive correlation between the velocity and hydrogen peroxide concentration. In addition, high efficient targeted identification and enrichment abilities were demonstrated based on the magnetic imprinted layer. No obvious interference was found from complicated matrices such as seawater samples, along with a real-time visualization of the protein loading and transport. Related studies would not only enrich the research connotations of protein imprinting, but also push forwards the development of multi-functionalized intelligent devices and strategy.(4) Quantum dots based mesoporous structured imprinting microspheres for the sensitive fluorescent detection of phycocyaninHerein, using phycocyanin as template via a sol–gel process, we developed a novel fluorescent probe for specific recognition and sensitive detection of phycocyanin by quantum dots based mesoporous structured imprinting microspheres, obeying electron-transfer-induced fluorescence quenching mechanism. In the presence of phycocyanin, a Meisenheimer complex would be formed between phycocyanin and primary amino groups on the surface of the QDs, and then the photoluminescent energy of QDs would be transferred to the complex and then result in QDs fluorescence quenching. The Si O2@QDs@ms-MIPs produced a significantly reduced fluorescent intensity and accordingly presented a satisfactory linearity in the range of 0.02–0.8 μM and a high detectability of 5.9 n M. Moreover, recoveries ranging from 94.0–105.0% were attained for spiked seawater and lake water samples with three concentration levels of phycocyanin. The study provided an effective way to develop fluorescent probes for convenient, rapid recognition and detection of trace proteins from complex matrices, and further pushed forward protein imprinting research.(5) Hg2+ ion-imprinted polymers sorbents based on dithizone-Hg2+ chelation for mercury speciation analysis in environmental and biological samplesNovel Hg2+ ion-imprinted polymers were synthesized by sol–gel process, using the chelate of dithizone and Hg2+ as template and APTES as functional monomer, followed by solid-phase extraction and atomic fluorescence spectroscopy detection, for mercury speciation analysis in environmental and biological samples. The resultant Hg-IIPs offered high binding capacity and fast kinetics. The IIPs displayed excellent selectivity toward Hg2+ over its organic forms and other metal ions, as well as high anti-interference ability for Hg2+ confronting with common coexistent ions. Moreover, by virtue of the chelation of dithizone, the IIPs could readily discriminate Hg2+ from organic mercury. The method was validated by using two certified reference materials with very consistent results. The IIPs-SPE-AFS demonstrated great application perspectives for rapid and high-effective cleanup, enrichment and determination of trace mercury species in complicated matrices.