| With the fast development of nanotechnology, more and more novel functional nanomaterials have been discovered, which allows highly specific and selective rapid detection of chemical pollutants. Specific recognition and effective response is the key piont for the establishment of rapid detection technologies. Therefore, researchers in analytical chemistry have focused on establishing highly specific and selective rapid detection technology. In this thesis, we prepared magnetic molecularly imprinted polymer, functional gold nanoparticles and Au NPs/Cd Te fluorescent probes with molecular recognition properties by funcational modification and multivariate hybridization of Fe3O4 and Au NPs. The structure and properties of the prepared functional nanomaterials were characterized to reveal their molecular recognition properties and molecular mechanism. Thereafter, these functional nanomaterials were used as core recognition units to build four kinds of optical sensors by combining different signal transduction mechanisms for sensitive and rapid detection of atrazine and triadimenol in irrigation water.Preparation of fluorescent optical sensor is based on bionic recognition technique of functional magnetic surface materials. The novel magnetic chitosan molecularly imprinted polymer(CS-MMIP) was prepared onto the surface of magnetic chitosan nanoparticle by radical polymerization and used to specifically recognize atrazine. The structure and properties of the prepared functional nanomaterials were characterized by fourier transform infrared spectra, transmission electron microscopy, X-ray powder diffractometer and vibrating sample magnetometer. The result showed the size of the CS-MMIP is about 1.2 μ m and the material had a rough porous structure and good magnetic property. Further studies suggested the absorption experiments and mechanism researches indicated that adsorption kinetics curves was inearized pseudo second-order kinetic model and static adsorption isotherm curves was in good agreement with Langmuir absorption isotherm and the imprinted factor was 2.14. Then, we exploited the benefits of efficient molecular recognition capacity of the CS-MMIP with competitive fluorescence assay to build fluorescent optical sensor for the atrazine detection in the range of 2.32-185.4 μ M. The detection limit for atrazine was 0.86 μ M(3SD/k).Preparation of colorimetric optical sensor is based on the color change of Au NPs induced by the hydrogen-bonding interaction. Au NPs prepared by the citrate-mediated reduction had controllable particle diameters. Melamine-Au NPs(Mel-Au NPs) was synthesized by self-assembly technology, which can take the advantages of molecular recognition and signal transduction properties, thus endowing the detection method with high sensitivity and the rapid detection period. The molecular recognition properties and molecular mechanism was studied by using UV-vis spectra, fourier transform infrared spectra, transmission electron microscopy and dynamic Light Scattering. Atrazine has a high ability to link to melamine through hydrogen-bonding, which results in the aggregation of Mel-Au NPs and the redshift of surface plasma resonance peak position. With an increasing atrazine concentration, the color changes from wine red to blue and the molecular recognition had been translated directly into UV-vis signals. Then, we built fluorescent optical sensor based on molecular recognition and signal transduction mechanisms for the atrazine detection in the range 0.165-330 μM. The detection limit of this colorimetric assay was as low as 16.5 n M(3SD/k) and the detecion period was 15 min.Preparation of colorimetric optical sensor is based on the specifically and selectively recognition property of functional magnetic C3N4 and the color changing effect of Au NPs. The novel magnetic C3N4 molecularly imprinted polymer(C3N4-MMIP) was prepared based on surface molecularly imprinted technology for specifically and selectively recognizing atrazine to avoid matrix interferences. The structure and properties of the prepared functional nanomaterials were characterized by fourier transform infrared spectra, transmission electron microscopy, X-ray powder diffractometer and vibrating sample magnetometer. The result revealed the size of the C3N4-MMIP is about 2 μ m and the material had a rough porous structure and good magnetic property. Further absorption experiments and mechanism researches indicated that adsorption kinetics curves was inearized pseudo second-order kinetic model and static adsorption isotherm curves was in good agreement with Freundlich absorption isotherm and the imprinted factor is 2.08. Then, we exploited the benefits of efficient molecular recognition and solid phase extraction capacity of the C3N4-MMIP with the color change effect of Au NPs to build colorimetric optical sensor for the atrazine detection in rice with the range 0.155-31.0 μ M. The detection limit for atrazine was 0.0765 μ M(3SD/k).Preparation of UV-vis/fluorescent optical sensor is based on the aggregation effect of Au NPs induced by the electrostatic interaction and fluorescence resonance energy transfer interaction of Au NPs/Cd Te. The Au NPs/Cd Te fluorescent probe was synthesized based on the electrostatic self-assembly technique, which exploited the benefits of high specificity and selectivty of fuorescence assay with simple, rapid sensitive colorimetic assay. The molecular recognition properties and molecular mechanism was studied by using UV-vis spectra, fourier transform infrared spectra, transmission electron microscopy and dynamic Light Scattering. The mechanism researches indicated that triadimenol could induce Au NP s to aggregate through electrostatic recognition interactions and caused the redshift of surface plasma resonance peak position, which will block fluorescence resonance energy transfer and result in fluorescence recovery of Cd Te. Then, we built UV-vis/fluorescent optical sensor based on molecular recognition and signal transduction mechanisms for the triadimenol detection in the range 0.338 μM-33.8 μM. The detection limit of this assay was 0.182 μM(3SD/k) and the detecion period was 20 min. |
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