Application Of Quantum Dots And Its Surface Imprinting Polymers To Chemiluminescence Analytical Method

Molecularly imprinted polymers (MIPs) are chemically systhetic functional polymeric materials that have biomimic properties. The imprinting process is performed by co-polymerising functional and cross-linking monomers in the presence of a template molecule. The subsequent removal of the imprint molecule reveals binding sites in the polymer network, which are complementary to the template in size and shape. That allows the highly specific rebinding of the template. In this thesis, we use different methods to synthesize the molecular imprinting polymers to separate the template (4-nitrophenol) from the environment samples and determine the amount by chemiluminescence method. The thesis is divided by four chapters, as described below:1.The developing history, the basic principle of molecularly imprinting technique and the preparation techniques were firstly reviewed. Then we summarized the advantages and disadvantages of the methods that be used to synthesize the molecular imprinting polymers and have a outlook of the development in molecular imprinting technique.2. In this work, different types of Mn-doped ZnS QDs were prepared and applied to the study of the chemiluminescence reaction of hydrogen peroxide and periodate. The effects of the size of nanoparticles, shell protection and the stabilizing agents on chemiluminescence intensity were studied. The results indicated that the size of quantum dots was not the only factor to enhance the intensity of chemiluminescence system. Different stabilizing agents and the silica film protection will also influence the performance of the quantum dots in the chemiluminescence reaction. A CL spectrum was examined by using a series of high-energy cut-off optical filters and a possible mechanism of the CL was also proposed.3. Molecular imprinting technique (MIT) demonstrates a promising way to separate the tailor analytes from complex matrix. In this chapter, Mn-doped ZnS quantum dots (QDs) capped by a molecule imprinting polymer (MIP) was synthesized. The results showed a high selectivity of the MIP-capped Mn-doped ZnS QDs towards the template molecule (4-nitrophenol) by QDs fluorescence quenching. The application of MIP-capped Mn-doped ZnS QDs to chemiluminescence (CL) system was also carried out in our work. This application combines the good selectivity of MIT with the high sensitivity of CL. The linear range of this CL system is from 0.1 to 40μM and the limit of detection (LOD) for 4-nitrophenol in the water can reach 76 nM. The method was also used to analysis of the real water samples and the recoveries were within the range of 91% to 96%.4. In this chapter, we compared the bulk and surface imprinting methods to synthesize the molecular imprinting polymers and the characterization experiments are also carried out. According to the results obtained in batch binding experiments, we can see that the surface imprinting polymers have more accessible sites, fast mass transfer and binding kinetics.