| With the development of agriculture,printing and dyeing industry and chemical industry,pesticides,dyes and phenols as three representative pollutants are inevitably discharged into environment water.Despite the concentration of pollutants is low,the water ecosystem is severely damaged.Furthermore,these pollutants can affect the nervous system,immune system,endocrine system and cardiovascular system of mammals.Therefore,it is urgent to develop a sensitive analytical method to detect the residual organic pollutants in the environmental water.Comparing the conventional detection method,surface enhanced raman scattering?SERS?technique,as an advanced analytical method,is gradually employed into the organic pollutants detection depending on the high-sensitivity,high-distinguishability,and lossless property.However,the ingredients of practical samples are very complex and contain analogues,so it is in urgent need to explore a SERS sensor containing selective property for organic pollutants detection.Molecular imprinted polymers?MIPs?contain the specific cavities which can be selectively matched with the templates.Therefore,combining SERS and molecular imprinting technique?MIT?to prepare the SERS imprinted sensor can effectively solve the disadvantages of traditional SERS.SERS imprinted sensor can detect the templates selectively.Moreover,the imprinted polymers coated on the surface of substrate can effectively prevent the substrate to be oxidized,which can maximally promote the sensitivity and cyclicity of the SERS imprinted sensor.In this paper,Ag particles,Ag-semiconductors composites,and Ag-r GO were used as the SERS substrates,respectively.Then cyhalothrin?LC?,Rhodamine?R6G?and2,6-dichlorophenol?2,6-DCP?were used as the templates and the MIT was combined to prepare the SERS sensor by precipitation polymerization and atom transfer radical polymerization?ATRP?technique.The main study results of this thesis are as follows:1.Preparation of SERS imprinted probe based on micro-nanometer argentum and research of selective detection perfmance.?1?The Ag particles with different surface morphologies were prepared under the assistance of small acid molecules to applied into the LC detection.Through the SERS investigation of different Ag morphologies,the Ag particles with?wool-ball?surface morphology presented perfect SERS capacity.Then,the Ag particles with?wool-ball?surface morphology were used as the SERS substrate and combined with the technique of molecule imprinting to prepare SERS-MIPs for the LC detection in the river.Under the optimal investigation condition,it was presented good linear relationship between the Raman signal(1595 cm-1)and the concentration of the templates(10-0.1?mol·L-1)and the limit of detection was 0.013?mol·L-1.The 5times recycle experiments were proved that the adsorption capacity of Ag-MIPs to LC decreased 12%,which proved that the material was stable and recyclable.Meanwhile,the selective experiment was proved that this material owned specific selectivity to the template.The practical water samples detection proved that the recoveries were from 96.70%to 103.60%and the material could be used into the LC detection in practical water.?2?The amino-functionalized SiO2 nanospheres were used as the supporting materials for the immobilization of Ag nanoparticles on the surface by the function of coordination between Ag+and—NH2.Then,it was used that the Rhodamine 6G?R6G?as the template to prepare the core-shell molecular imprinted polymers.Prominently,the shell thickness could be controlled by the regulation of cross-linker dosage and it was found that the SERS detection signal was most obvious when the shell thickness was about 40 nm.Under the optimal condition,it was presented good linear relationship between the Raman signal(at 1505 cm-1)and the concentration of the templates(10-6-10-12 mol·L-1)and the limit of detection was 10-12 mol·L-1.Meanwhile,the selective experiment was proved that this materials owned specific selectivity to the template.2.Preparation of SERS imprinted probe based on argentum-metallic oxide substrate and research of selective detection perfmance.?1?It was developed the Fe3O4@SiO2 as support materials to reduce loss and anchor Ag nanoparticles on the surface as the SERS substrates.Then the Fe3O4@Ag@MIPs was prepared by precipitation polymerization and it was evaluated as the SERS imprinted sensor for selective detection of 2,6-dichlorophenol?2,6-DCP?from aqueous medium.The resulting materials were characterized by modern analysis measurement and the results demonstrated Fe3O4@Ag@MIPs exhibiting good magnetic separation,sensitive detection and selectivity.The 5 times recycle experiments were proved that the adsorption capacity of Fe3O4@Ag@MIPs to2,6-DCP decreased 10%,which proved that the material was stable and recyclable.Under the optimal condition,it was presented good linear relationship between the Raman signal(at 1596 cm-1)and the concentration of the templates(200-1 nmol·L-1)and the limit of detection was 0.19 nmol·L-1.The practical water samples detection proved that the recoveries were from 98.31%to 102.17%and the material could be used into the 2,6-DCP detection in practical water.?2?The ZnO/Ag heterostructures were used as the SERS substrates,R6G as template,NIPAAm as thermoresponsive monomer to prepare the thermoresponsive ZnO/Ag/molecularly imprinted polymers?ZOA-TMIPs?.It was proved from the analysis results that the SERS property of ZOA-TMIPs was significantly influenced by temperature.When the temperature was 30oC,the Raman signal was distinct.Under the optimal condition,it was presented good linear relationship between the Raman signal(at 1653 cm-1)and the concentration of the templates(10-7-10-13mol·L-1)and the limit of detection was 10-13 mol·L-1.The selective experiment was proved that this materials owned specific selectivity to the template.Meanwhile,it was proved that the ZOA-TMIPs owned the property of self-cleaning under the condition of ultraviolet light and it could degradate the R6G adsorbed on the surface of ZOA-TMIPs.3.Preparation of SERS imprinted probe based on argentum-reduced graphene oxide and research of selective detection perfmance.?1?SiO2@rGO@Ag composites were selected as the substrates.Then,SERS imprinted sensor?SGA-MIPs?was synthesized by two steps:firstly,the SiO2@rGO@Ag composites were modified with amidogen on the surface by the self-polymerized process of dopamine.Secondly,a surface-initiated atom transfer radical polymerization?ATRP?procedure was carried out for the preparation of SGA-MIPs using LC as the templates.The results proved that the SERS property of rGO-Ag was more significant than Ag particles.The 7 times recycle experiments were proved that the adsorption capacity of SGA-MIPs to LC decreased 11%,which proved that the material was stable and could be circularly applied.Through the modern instruments analysis results,the SGA-MIPs exhibited perfect SERS detection properties and selectivity.The Raman intensity(at 1004 cm-1)and LC concentration(10-5-10-9 mol·L-1)presented perfect linear relationship and the detection limit was10-9 mol·L-1.The practical water samples detection proved that the recoveries were from 98.71%to 104.67%and the material could be used into the LC detection in practical water.?2?In this work,a strategy was presented that Ag-reduced graphene-Ag multilayered structures?Ag@rGO@Ag?was used as the SERS substrates and modified with dopamine for the development of molecular imprinted composite sensor?AGA-MIPs?used into selective detection of chlorophenol in the river.The AGA-MIPs was synthesized using 2,6-Dichlorophenol?2,6-DCP?as template,through the technique of ATRP.It was proved that the noble metal particles dispersed on the both sides of graphene the SERS properties would enhance the Raman signal.Notably,in order to enhance the imprinted capacity,two functional monomers?acrylamide and methacrylic acid?were selected.The AGA-MIPs presented excellent specific selectivity and sensitivity to the templates.The effect of synthesis condition on the selective recognition behavior of AGA-MIPs was also examined.The Raman intensity(at 659 cm-1)and 2,6-DCP concentration present perfect linear relationship when the concentration was between 10-5-10-10 mol·L-1 and the detection limit was10-10 mol·L-1.The approach provided a simple technique and could be used into pyrethroid detection in the practical water sample without causing any pollution. |
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