【作者】 熊艳；

【导师】 章竹君；

【作者基本信息】 西南大学 ， 分析化学， 2006， 硕士

【摘要】 化学发光(Chemiluminescence,CL)是化学反应体系中,某些物质分子,如反应物、中间体或者荧光物质吸收了反应释放的能量而由基态跃迁至激发态,电子通过振动松弛和内转换,以非辐射跃迁回到第一电子激发态的最低振动能级,然后以光辐射的形式释放能量回到基态,从而产生化学发光。化学发光分析法具有灵敏度高、仪器设备简单、分析速度快、操作方便等特点,广泛地应用于环境化学、临床检验、药物分析和工业分析等领域。但是,由于化学发光分析法选择性差,限制了该方法在复杂样品中的应用。为了提高化学发光分析法的选择性,化学研究者主要从两个方面来考虑:一是和高分离效能的分离方法相结合,如高效液相色谱(HPLC)、毛细管电泳(CE)等,这些方法操作比较复杂,所需仪器设备比较昂贵;另一方面是将化学发光与特异性的分子反应识别相结合,包括化学识别,酶识别(纯酶、动植物组织和细胞),抗体—抗原识别,核酸识别,DNA识别和蛋白质识别等。这些识别技术存在的主要问题是其稳定性较差。 分子印迹技术(molecular imprinting technique,MIT)是一种新型的识别技术,它集高分子合成、分子设计、分子识别、仿生生物工程等众多学科优势发展起来的一门新兴技术。分子印迹聚合物由于具有与天然抗体同样的识别性能和与高分子同样的抗腐蚀性能的双重优点,因而广泛应用于生物工程、临床医学、环境监测、食品工业等众多领域。 本论文的主要内容是分子印迹技术在化学发光传感器及固相萃取中的分析应用。全文由两部分组成。 第一部分详细介绍了分子印迹技术的基本原理和分子印迹聚合物(Molecularly imprinted polymer,MIP)的制备方法,综述了近十年来该技术在分析化学领域中的应用及发展情况。 第二部分报告了两方面的内容。一是报告了以分子印迹聚合物作为识别物质的化学发光传感器的研究工作。内容包括运用分子印迹技术分别合成了以降血压药物肼屈嗪、抗结核药物异烟肼、降血糖药物甲福明为模板的分子印迹聚合物,并将其识别能力应用于化学发光传感器中,大大地提高了化学发光分析法的选择性,使该化学发光传感器能直接测定复杂样品中的分析物。二是报告了分子印迹结合化学发光在固相萃取中的研究工作。在该部分中,运更多还原

【Abstract】 Chemiluminescence (CL) analysis has been widely used in many fields due to its attracting features including simplicity, low detection limit, wide linear dynamic range, rapid analysis speed and inexpensive instruments. However, the relatively poor selectivity of the CL method itself limits its direct application to the analysis of analyte in complicated sample. Great efforts were made to improve the selectivity of CL analysis mainly from two aspects. One aspect was to combine CL method with some separation techniques such as high performance liquid chromatography (HPLC) and capillary electrophoresis (CE), but these methods required relatively complicated and expensive instruments. The other aspect was to combine CL method with special molecule recognition, including chemistry recognition, enzyme recognition, antibody-antigen recognition, nucleic acid recognition, DAN recognition, protein recognition and so on. The main problem existing in these methods is their poor stability.Molecularly imprinting technology (MIT) is a novel molecule recognition technology, which prepares the polymer that has special recognition and selectivity function for template molecule. Molecularly imprinted polymer (MIP) not only has excellent special recognition capacity compared with enzyme-substrate, antibody-antigen, receptor-ligand, but also has attractive features such as physical robustness, high strength, resistance to elevated temperatures and pressures, and inertness towards acids, bases, metal ions and organic solvents. Due to the high selectivity and stability of the MIP, MIP has been applied in several analytical fields such as sensor devices, chromatography separation, mimic enzyme, membrane, immune analysis etc. Using MIP as recognition element in FIA-CL sensor, the selectivity and sensitivity of the CL method would be greatly improved due to the special recognition capacity and binding capacity of MIP respectively.The thesis is divided into two parts. Part one describes MIT in details and reviews recentdevelopment and application in analytical chemistry during recent ten years. Part two includes two aspects. The first aspect describes the studies of CL sensors using MIP as recognition elements respectively. The second aspect describes the application of MIP as recognition elements in SPE combined with CL analysis for analyte determination.1. Determination of hydralazine with flow injection chemiluminescence sensor using molecularly imprinted polymer as recognition elementA novel flow injection chemiluminescence (CL) sensor for hydralazine determination using molecularly imprinted polymer (MIP) as recognition element is reported. Hydralazine-MIP was prepared through non-covalent copolymerization using methacrylic acid (MAA) monomer, hydralazine template and ethylene glycol dimethacrylate (EGDMA) cross-linker. Particles of the MIP were packed into a v shape glass tube for on-line adsorption of the analyte of hydralazine. The adsorbed hydralazine could be sensed by its great enhancing effect on the CL reaction between luminol and periodate. The CL intensity is linear to hydralazine concentration in the range from 2*10"9to 8X10’7g/mL. The detection limit is 6xlO"log/mL (3 0 ) and the relative standard deviation is 2.8% (n=7) for 8X 10’9g/mL hydralazine. The selective experiment showed that the selectivity and sensitivity of the CL method could be greatly improved when MIP was used as recognition element in the flow-injection CL sensor. The sensor was reversible and reusable. It could be used for more than 100 times. It has been used directly to determine the hydralazine in human urine.2. Flow-injection chemiluminescence sensor for determination of isoniazid in urine sample based on molecularly imprinted polymerIn this paper, molecularly imprinted polymer (MIP) of isoniazid is synthesized through thermal radical copolymerization of metharylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) in the presence of isoniazid template molecules. A novel flow injection chemiluminescence sensor for isoniazid determination is developed by packing the isoniazid-MIP into the flow cell as recognition elements. Isoniazid could be selectively adsorbed by the MIPs and the adsorbed isoniazid was sensed by its great enhancing effect on the weak CL reaction between luminol and periodate which were mixed in the flow cell. The enhanced CL intensity is linear in the range 2*10’9 to 2xlO"7g/mL and the detection limit is 7><10"10g/mL (3a) isoniazid with a relative standard deviation 2.8% (n=9) for 8xl0’VmL. The sensor is reversible and reusable. Ithas a great improvement in sensitivity and selectivity for CL analysis. As a result, the sensor has been successfully applied to determination of isoniazid in human urine. At the same time, the binding characteristic of the polymer to isoniazid was evaluated by batch method and the dynamic method respectively.3. A chemiluminescence sensor for determination of metformin in urine sample based on molecularly imprinted polymerIn this work, molecularly imprinted polymer of metformin was synthesized and a chemiluminescence sensor was prepared using the polymer as recognition material for determination of metformin. NBS and fluorescein reacted with metformin to produce strong CL. The CL intensity was linear to metformin concentration in the range from 2><10" to 8x10" g/mL. The detection limit was 6xl0"9g/mL and the R.S.D. was less than 5% (n=9). The selective experiment showed that it could greatly improve the selectivity of CL method when MIP was applied to CL. The sensor was reversible and could be used for more than 100 times. It has been used to determine the metfomin in human urine.4. Molecularly imprinted on-line solid-phase extraction combined with flow-injection chemiluminescence for the determination of tetracyclineA molecularly imprinted polymer solid phase extraction (MISPE) method combined with flow-injection chemiluminescence (FI-CL) for tetracycline (TC) determination has been developed. A molecularly imprinted polymer (MIP) of tetracycline was synthesized and particles of this MIP were packed into a polytetrafluoroethylene (PTFE) tube. This tube was employed as MISPE micro-column and was connected into the sampling loop of the eight-way injection valve for tetracycline preconcentration and extraction. After the sample flowed through the MISPE micro-column, tetracycline was adsorbed and preconcentrated on the MIPs. Then eluent (CH3CN:HNO3 (O.Olmol L"1) = 4:1, v:v) was used as carrier for extracting the adsorbed tetracycline to react with cerium (IV) and rhodamine B mixed in the flow cell to produce strong CL. The conditions of preconcentration, elution and CL reaction were carefully studied. CL intensity was linear with tetracycline concentration from 4x 10"9 to 4x 10"7 g mL"1 and the detection limit was lxlO"9g mL"1 (3o) with a relative standard deviation (R.S.D.) 2.4% (n=9). The selectivity of MISPE micro-column and binding capacity of the MIP were evaluated. However, the MIP micro-column interacted indiscriminately with oxytetracycline with a 49±2% binding. Anintermediate step of differential pulsed elution (DPE) using 3% acetic acid as eluent was employed to remove oxytetracycline and other structural analogues. This method has been successfully applied to determinate tetracycline in fish sample.更多还原