基于水滑石—壳聚糖复合材料辣根过氧化物酶传感器的构筑

发布时间：2018-07-09 10:15

本文选题：水滑石 + 壳聚糖　；参考：《湘潭大学》2017年硕士论文

【摘要】：水滑石在电化学领域的应用主要是利用其自身层板金属原子电活性或者以其为载体固定酶等大分子,但存在成膜较脆、易溶胀脱落、粘性小等缺点,限制了其在电化学方面的应用。壳聚糖作为优良生物膜材料,具良好的黏附性、透过性和生物相容性,将两者有机复合制备的纳米复合材料可兼具水滑石和壳聚糖的特性,使其在电化学、催化反应、新能源等领域有着重要的作用。本论文着力于制备水滑石-壳聚糖复合材料(LDH-CHT),以此为载体固定辣根过氧化物酶(HRP),制备复合基体材料(LDH-CHT/HRP),并将其修饰于电极表面制备酶电极(LDH-CHT/HRP/GCE),从而构建一种性能优良的新型H2O2的HRP传感器,以实现对H2O2的快速安培响应检测。具体研究工作如下:采用尿素法制备了不同Zn/Al摩尔比的ZnAl-水滑石(ZnAl-LDHs)纳米材料,结合各种表征分析表明,Zn/Al摩尔比为3的ZnAl-LDH结晶度和层间规整度高,且其表面永久正电荷密度大,导致其具高电化学性能。该水滑石修饰电极(LDH/GCE)的电化学反应过程为准可逆反应,受扩散步骤和电化学反应混合控制,LDH能够提供良好的电化学传感界面。成功制备了一种新型的水滑石-壳聚糖复合材料(LDH-CHTs)。通过各种表征手段研究表明,LDH-CHTs仍具典型水滑石晶体结构。壳聚糖的适量添加可增大复合材料的比表面积,增加孔道数量和提高表面永久电荷密度。其中,壳聚糖添加量为2.0 g/L时制备的水滑石-壳聚糖复合材料(LDH-CHT)具有高结晶度、大比表面积和高表面永久正电荷密度。对其进行电化学性能测定,表明其电化学性能高于纯水滑石修饰电极。壳聚糖与水滑石复合制备的LDH-CHT可增强其修饰电极表面的电化学稳定性,进一步提高其电化学性能,为制备良好的电化学传感界面提供可能。以LDH-CHT为载体和导电介质固定HRP,成功制备了HRP固定化酶基体材料(LDH-CHT/HRP),将其修饰电极表面HRP制备酶电极(LDH-CHT/HRP/GCE),用于构建一种性能优良的新型H2O2的HRP传感器。该传感器的灵敏度较高、选择性高、稳定性和重现性好,具有较低的米氏常数(Km=6.889)。对H2O2的线性检测范围为2.0×10-5~6.1×10-3 mol/L,检出限为2.04×10-6 mmol/L(S/N=3)。HRP传感器展示了良好的传感性能,可实现对H2O2的快速安培响应。
[Abstract]:The application of hydrotalcite in the electrochemical field mainly uses its own laminate metal atom electric activity or immobilized enzyme with it as the carrier, but it has the disadvantages of brittle film formation, easy swelling and falling off, low viscosity and so on. Its application in electrochemistry is limited. Chitosan, as an excellent biomembrane material, has good adhesion, permeability and biocompatibility. The nanocomposites prepared by organic combination of the two materials can have the characteristics of hydrotalcite and chitosan, and make them react in the electrochemical and catalytic ways. New energy and other fields play an important role. In this thesis, hydrotalcite-chitosan composite (LDH-CHT) was prepared by immobilization of horseradish peroxidase (HRP) on the substrate and preparation of composite matrix material (LDH-CHT-HRP / GCE), which was modified on the surface of the electrode to prepare an enzyme electrode (LDH-CHT-HRP / GCE). A new type of H2O2 HRP sensor, In order to realize the rapid amperometric response detection of H _ 2O _ 2. The main results are as follows: ZnAl- hydrotalcite (ZnAl-LDHs) nanomaterials with different Zn / Al molar ratios were prepared by urea method. The results of various characterization analysis showed that ZnAl-LDH with Zn / Al molar ratio 3 had high crystallinity and interlaminar regularity, and its surface permanent positive charge density was high. It has high electrochemical performance. The electrochemical reaction process of the water talc modified electrode (LDH / GCE) is quasi-reversible, and LDH can provide a good electrochemical sensing interface controlled by the diffusion step and the electrochemical reaction mixture. A novel hydrotalcite-chitosan composite (LDH-CHTs) was successfully prepared. The results show that LDH-CHTs still have typical hydrotalcite crystal structure. The addition of chitosan can increase the specific surface area, increase the number of pores and increase the surface permanent charge density. The hydrotalcite / chitosan composite (LDH-CHT) prepared by adding 2.0 g / L chitosan has high crystallinity, large specific surface area and high surface permanent positive charge density. The electrochemical performance of the modified electrode is higher than that of the pure water talc modified electrode. The LDH-CHT prepared by chitosan and hydrotalcite can enhance the electrochemical stability of the modified electrode and further improve its electrochemical performance, which provides the possibility for the preparation of a good electrochemical sensing interface. Using LDH-CHT as carrier and conducting medium to immobilize HRP, the HRP immobilized enzyme matrix material (LDH-CHT-HRP) was successfully prepared. The surface HRP of the modified HRP electrode (LDH-CHT-HRP / GCE) was used to construct a new type of HRP sensor with excellent properties of H _ 2O _ 2. The sensor has high sensitivity, high selectivity, good stability and reproducibility, and has low Michlet constant (KmC6.889). The linear detection range of H _ 2O _ 2 is 2.0 脳 10 ~ (-5) (6.1 脳 10 ~ (-3) mol / L), and the detection limit is 2.04 脳 10 ~ (-6) mmol / L (S / N ~ (3). The HRP sensor shows good sensing performance and can achieve a rapid amperometric response to H _ 2O _ 2.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TP212

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