核—壳结构金丝桃素分子印迹磁纳米球的简便制备方法研究

发布时间：2018-08-07 18:25

【摘要】：作为贯叶连翘的主要活性成份,金丝桃素具有抗菌消炎、抗抑郁、抗病毒、抗癌等一系列的药理活性受到人们的重视。但是,贯叶连翘中金丝桃素的含量极低,导致从植物中提取困难,提取效率低下。分子印迹聚合物技术因其可赋予材料对特定分子的特异性识别和吸附能力成为解决金丝桃素提取问题的有效途径之一。基于此,我们以Fe3O4为基体,多巴胺为功能单体和交联剂,在金丝桃素的存在下,通过多巴胺的氧化自聚形成一种具有结构的表面分子印迹聚合物纳米球(Fe3O4@PDA/Hyp)。论文首先采用FTIR、TEM、DLS、Zeta电位和BET等技术对合成的各种磁纳米球(包括基体磁纳米球、金丝桃素印迹和非印迹磁纳米球)进行了表征。结果表明多巴胺可以在磁球表面生成厚度介于23-29纳米的聚多巴胺(PDA)薄膜,从而形成稳定的结构纳米粒子。然后对影响金丝桃素分子印迹磁纳米球(Fe3O4@PDA/Hyp)印迹效果的合成条件,包括多巴胺的浓度、丙酮的含量、模板分子和功能单体的比、反应温度、反应介质的p H、反应物的添加顺序以及是否进行乙醇胺处理等进行了研究。通过比较不同条件下制备的Fe3O4@PDA/Hyp纳米球对金丝桃素吸附量的大小,确定了其最佳合成条件,即:在室温条件下,首先将金丝桃素模板分子加入到基体磁珠的悬浮液中,随后加入多巴胺单体进行聚合。其中多巴胺的浓度为2mg/mL,丙酮与Tris-HCl的体积比为1:6,金丝桃素与多巴胺的摩尔比为1:122,溶液的pH为8.0。最后,对制备的纳米球用乙醇胺进行处理以获得最终的Fe3O4@PDA/Hyp磁纳米粒子。在此条件下制备的Fe3O4@PDA/Hyp磁纳米球对于金丝桃素的吸附量为18.28 mg/g。以原金丝桃和大黄素作为金丝桃素的结构类似物,对Fe3O4@PDA/Hyp磁纳米球的特异识别能力进行研究,发现其对原金丝桃和大黄素的选择因子SF分别为1.92和3.55,其对金丝桃素、原金丝桃和大黄素的印迹因子IF分别8.01、3.07和1.36,表明本工作制备的Fe3O4@PDA/Hyp磁纳米球对金丝桃素模板分子具有令人满意的识别能力和印迹效果。对该纳米球吸附动力学研究表明,其对金丝桃素分子的吸附符合Langmuir的吸附模型。实际应用初步研究发现,本工作制备的Fe3O4@PDA/Hyp磁纳米球对贯叶连翘提取液中的金丝桃素具备较好的选择性识别和吸附能力。该方法制备简便,制备的Fe3O4@PDA/Hyp磁纳米球对金丝桃素具有较好的选择性识别和吸附能力,有望用作金丝桃素富集和分离的吸附材料。
[Abstract]:As the main active component of Hypericum perforatum, hypericin has a series of pharmacological activities, such as anti-inflammatory, anti-depressant, anti-virus, anti-cancer and so on. However, the content of hypericin in Hypericum perforatum was very low, which led to the difficulty of extracting from plants and the low extraction efficiency. Molecularly imprinted polymer technology has become one of the effective ways to solve the problem of extraction of hypericin because of its ability of specific recognition and adsorption to specific molecules. Therefore, in the presence of hypericin, a surface molecularly imprinted polymer nanospheres (Fe3O4@PDA/Hyp) were formed by oxidation self-polymerization of dopamine with Fe3O4 as matrix, dopamine as functional monomer and crosslinking agent. The synthesized magnetic nanospheres (including matrix magnetic nanospheres, hypericin imprinted and non-imprinted magnetic nanospheres) were characterized by FTIR Tem Tem DLS Zeta potential and BET. The results show that dopamine can form polydopamine (PDA) thin films with thickness of 23-29 nanometers on the surface of magnetic spheres, thus forming stable structured nanoparticles. Then the synthetic conditions affecting the imprinting effect of hypericin molecularly imprinted magnetic nanospheres (Fe3O4@PDA/Hyp) were studied, including the concentration of dopamine, the content of acetone, the ratio of template molecule to functional monomer, the reaction temperature, The pH of the reaction medium, the addition order of reactants and the treatment of ethanolamine were studied. By comparing the amount of hypericin adsorbed by Fe3O4@PDA/Hyp nanospheres prepared under different conditions, the optimum synthesis conditions were determined: firstly, hypericin template molecule was added to the suspension of matrix magnetic beads at room temperature. Then dopamine monomer was added for polymerization. The concentration of dopamine is 2 mg / mL, the volume ratio of acetone to Tris-HCl is 1: 6, the molar ratio of hypericin to dopamine is 1: 122, the pH of solution is 8.0. Finally, the prepared nanospheres were treated with ethanolamine to obtain the final Fe3O4@PDA/Hyp magnetic nanoparticles. Under these conditions, the adsorption capacity of Fe3O4@PDA/Hyp magnetic nanospheres for hypericin was 18.28 mg / g. The specific recognition ability of Fe3O4@PDA/Hyp magnetic nanospheres was studied by using proto hypericin and emodin as structural analogues of hypericin. It was found that the selective factors SF for proto hypericin and emodin were 1.92 and 3.55, respectively. The imprinting factors of hypericin and emodin were 8.01 ~ 3.07 and 1.36, respectively, which indicated that the Fe3O4@PDA/Hyp magnetic nanospheres had satisfactory recognition ability and imprinting effect on hypericin template molecule. The adsorption kinetics of the nanospheres showed that the adsorption of hypericin was in accordance with the Langmuir adsorption model. It is found that the Fe3O4@PDA/Hyp magnetic nanospheres prepared in this work have good selective recognition and adsorption ability for hypericin in the extract of Hypericum perforatum. The prepared Fe3O4@PDA/Hyp magnetic nanospheres have good selective recognition and adsorption ability for hypericin, which is expected to be used as an adsorptive material for hypericin enrichment and separation.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.3;TB383.1

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