四环素磁性分子印迹聚合物的制备、表征及应用研究

发布时间：2018-11-02 08:23

【摘要】：以四环素(TC)为模板,Fe_3O_4为载体,制备得到四环素磁性分子印迹聚合物(TC@Fe_3O_4@SiO2@MIP);TC碱性降解产物作为荧光标记物(Flu-TC),与TC竞争TC@Fe_3O_4@SiO2@MIP上的结合位点,磁性分子印迹荧光免疫竞争吸附方法,检测牛奶中的四环素类抗生素痕量残留。采用共沉淀法制备Fe_3O_4纳米粒子;通过氨水催化正硅酸乙酯(TEOS)水解作用将硅包覆在Fe_3O_4纳米粒子表面,用硅烷化试剂KH-570活化磁性纳米粒子;以表面分子印迹技术,TC为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂制备得到四环素磁性分子印迹聚合物(TC@Fe_3O_4@SiO2@MIP)。以电镜扫描(SEM)、红外光谱(IR)、振动样品磁强计(VSM)等技术手段对其形貌、结构和磁性进行了表征;研究了其对模板分子及类似物的吸附选择性,结果表明该聚合物对四环素具有较好的特异吸附性。拟合吸附等温数据和动力吸附数据,发现TC和TC@Fe_3O_4@SiO2@MIP之间的吸附过程遵循Freundlich吸附等温模型和准二级动力学。通过吸附实验和Scatchard方程进行分析,发现TC@Fe_3O_4@SiO2@MIP对四环素存在特异性和非特异性两种结合位点。四环素强碱条件下降解产物作为荧光标记物(Flu-TC),并以TC@Fe_3O_4@SiO2@MIP评价其吸附性能。结果显示,TC@Fe_3O_4@SiO2@MIP对Flu-TC具有一定的选择性识别性能,由此可建立磁性分子印迹荧光免疫竞争吸附方法。采用OasisHLB固相萃取小柱对牛奶进行样品前处理,与分子印迹荧光免疫竞争吸附分析法联用检测牛奶中痕量的四环素,检测限可达1Oppm。方法的绝对回收率为68%。研究结果表明:TC浓度在0.01mg/L-1mg/L范围内,线性关系良好,Y=-11.207x+24.197(R2=0.9896);在 1 mg/L-40mg/L 范围内,线性关系为Y=-0.4054x+14.124(R2=0.9782),样品平均加标回收率在 76.32%-89.92%,相对标准偏差小于10%。该方法结合磁性材料的快速分离、分子印迹材料的“类抗体”特异识别性、荧光免疫分析法灵敏度高、检测限低等优点,为快速检测牛奶中痕量四环素残留提供了一个新的选择。
[Abstract]:Tetracycline magnetic molecularly imprinted polymer (TC@Fe_3O_4@SiO2@MIP) was prepared by using tetracycline (TC) as template and Fe_3O_4 as carrier. The basic degradation product of TC was used as a fluorescent marker (Flu-TC) to compete with TC at the binding site of TC@Fe_3O_4@SiO2@MIP. Magnetic molecularly imprinted fluorescence competitive immunosorbent assay was used to detect trace residues of tetracycline antibiotics in milk. Fe_3O_4 nanoparticles were prepared by coprecipitation method, and then coated on the surface of Fe_3O_4 nanoparticles by (TEOS) hydrolysis of ethyl orthosilicate catalyzed by ammonia water. The magnetic nanoparticles were activated by KH-570. Surface molecular imprinting technique, TC as template molecule, 伪 -methacrylate (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, Tetracycline magnetic molecularly imprinted polymer (TC@Fe_3O_4@SiO2@MIP) was prepared by using azodiisobutyronitrile (AIBN) as initiator. The morphology, structure and magnetic properties were characterized by scanning (SEM), infrared spectroscopy (SEM), (IR), vibration sample magnetometer (VSM) and so on. The adsorption selectivity of the polymer to the template molecule and its analogues was studied. The results showed that the polymer had a good specific adsorption property for tetracycline. It is found that the adsorption process between TC and TC@Fe_3O_4@SiO2@MIP follows the Freundlich isotherm model and quasi-second-order kinetics. Through adsorption experiment and Scatchard equation, it was found that TC@Fe_3O_4@SiO2@MIP had two binding sites to tetracycline. The degradation product of tetracycline was used as a fluorescent label (Flu-TC) under the condition of strong base of tetracycline and its adsorption property was evaluated by TC@Fe_3O_4@SiO2@MIP. The results show that TC@Fe_3O_4@SiO2@MIP has a certain selective recognition performance for Flu-TC, so a magnetic molecularly imprinted fluorescent competitive immunosorbent method can be established. The OasisHLB solid-phase extraction column was used to pretreat the milk samples. The detection limit of tetracycline in milk was up to 1 Oppm by means of molecular imprinted fluorescence immunocompetitive adsorption assay. The absolute recovery of the method was 68%. The results showed that the concentration of TC in the range of 0.01mg/L-1mg/L had a good linear relationship, YTI-11.207x 24.197 (R2O0.9896); In the range of 1 mg/L-40mg/L, the linear relationship was YP0. 4054x 14.124 (R2C0. 9782). The average recovery of the sample was 76.32- 89.92, and the relative standard deviation was less than 10. This method combines the advantages of rapid separation of magnetic materials, specific recognition of "antibody like" of molecularly imprinted materials, high sensitivity of fluorescence immunoassay and low detection limit. It provides a new choice for rapid determination of trace tetracycline residues in milk.
【学位授予单位】：昆明医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631

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