多糖复合材料的制备及在手性识别和染料吸附中的应用

发布时间：2018-05-30 23:41

本文选题：多糖 + 手性识别　；参考：《常州大学》2017年硕士论文

【摘要】：构建马铃薯淀粉(PS)手性平台并将其应用于电化学识别色氨酸(Trp)对映体。由于PS对D-Trp具有更大的亲和力,因此PS更倾向于与D-Trp通过主客体相互作用而结合。当L-Trp和D-Trp分别与PS修饰电极表面接触时,L-Trp更容易通过PS的左手双螺旋结构而在电极表面被氧化。因此,PS修饰电极可以用于识别Trp对映体。水接触角实验首次被用于证明PS与Trp对映体之间具有不同的亲和力。同时,PS修饰电极对于Trp对映体的识别具有温度敏感性,这是由于PS与客体分子(Trp)之间形成的氢键的强弱受温度的影响。值得注意的是,在PS的主链上引入羟丙基基团后(H-PS),H-PS修饰电极对Trp对映体的识别效率明显降低,这可能是由于主客体反应过程中存在额外的空间位阻。羧甲基纤维素钠(NaCMC)可通过链上的羧基和壳聚糖(CS)链上的氨基发生酰胺化反应,从而可形成CMC-CS复合材料。与NaCMC和CS相比,当NaCMC和CS的质量比为1:1时生成的复合材料(CMC-CS(1:1))展现出三维多孔网络状结构,由于大量的极性官能团暴露在CMC-CS(1:1)三维多孔网络状结构以外,从而显著提高了CMC-CS(1:1)的亲水性。本章利用CMC-CS(1:1)复合材料构建了手性界面并将其应用于电化学识别Trp对映体。由于CMC-CS(1:1)高度亲水的特征以及在与Trp对映体形成氢键的过程中空间位阻不同,CMC-CS(1:1)手性界面对Trp对映体具有良好的选择性。同时,我们还对复合材料中NaCMC与CS的质量比和制备方式进行了优化。结果表明,CMC-CS(1:1)手性界面可以准确测定D-Trp在外消旋体溶液中的含量。在马铃薯淀粉凝胶化的过程中,将硫代苹果酸(MSA)分子引入到马铃薯淀粉的大分子链上,从而破坏了马铃薯淀粉链与链之间的固有氢键。通过傅里叶变换红外验证了这一过程。将MSA改性的马铃薯淀粉经过冷冻干燥后可以得到MSA改性的多孔淀粉干凝胶(PSX/MSA)。最后,将PSX/MSA应用于去除具有基因毒性的天然着色剂栀子黄(GY)。由于PSX/MSA具有多孔结构且MSA分子中存在羧基,PSX/MSA对GY的吸附能力远高于单一的淀粉干凝胶(SX)和马铃薯淀粉。
[Abstract]:The chiral platform of potato starch (PSN) was constructed and applied to electrochemical recognition of tryptophan (Trp) enantiomers. Because PS has more affinity to D-Trp, PS is more inclined to combine with D-Trp through the interaction of host and guest. When L-Trp and D-Trp are in contact with the surface of PS modified electrode, L-Trp is more likely to be oxidized on the electrode surface through the left-handed double helix structure of PS. Therefore, PS modified electrode can be used to identify Trp enantiomers. The water contact angle experiment was used for the first time to prove the different affinity between PS and Trp enantiomers. At the same time, the PS-modified electrode is temperature-sensitive to the recognition of Trp enantiomers, which is due to the influence of temperature on the hydrogen bond formed between PS and the guest molecule TRP. It is worth noting that the efficiency of Trp enantiomeric recognition is obviously reduced by introducing hydroxypropyl groups into the host chain of PS, which may be due to the existence of additional steric hindrance in the process of host and guest reaction. CMC-CS composites can be formed by amidation of carboxyl groups on the chain and amino groups on the chain of chitosan. Compared with NaCMC and CS, when the mass ratio of NaCMC and CS is 1:1, the composite material (CMC-CSC: 1: 1) exhibits a three-dimensional porous network structure, because a large number of polar functional groups are exposed to CMC-CSC 1: 1) three-dimensional porous network structure. Thus, the hydrophilicity of CMC-CSN 1: 1) was improved significantly. In this chapter, the chiral interface of CMC-CS1: 1) composite was constructed and applied to electrochemical recognition of Trp enantiomers. Because of the high hydrophilic character of CMC-CSC (1: 1) and the good selectivity of Trp enantiomers to Trp enantiomers due to the different steric hindrance in the formation of hydrogen bonds with Trp enantiomers, the chiral interfaces have good selectivity to Trp enantiomers. At the same time, the mass ratio of NaCMC to CS and the preparation method were optimized. The results show that the chiral interface of CMC-CSN 1: 1) can accurately determine the content of D-Trp in racemate solution. During the gelation of potato starch, the thiomalic acid (MSA) molecule was introduced into the macromolecular chain of potato starch, thus destroying the inherent hydrogen bond between the potato starch chain and the chain. This process is verified by Fourier transform infrared (FTIR). After freeze-drying of potato starch modified by MSA, MSA modified porous starch xerogel (PSX / MSAA) was obtained. Finally, PSX/MSA was used to remove gene-toxic natural colorant Gardenia jasminoides. Because of the porous structure of PSX/MSA and the presence of carboxyl group in MSA, the adsorption ability of PSX / MSA to GY is much higher than that of single starch xerogel and potato starch.
【学位授予单位】：常州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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