基于GO-ZnS构建的DNA传感器用于环境优先污染物的检测

发布时间：2018-01-06 10:08

本文关键词：基于GO-ZnS构建的DNA传感器用于环境优先污染物的检测　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文作者采用水热法制备了氧化石墨烯-硫化锌量子点(GO-ZnS)复合纳米材料,利用扫描电镜(SEM)、X射线衍射(XRD)对其表面形貌和成分进行了分析,以获得的GO-ZnS复合纳米材料修饰玻碳电极(GCE),大大提高了玻碳电极的伏安响应。基于GO-ZnS对电极界面电子传导的增强效应制备了一种新型的生物传感器,实现了对环境优先污染物的检测。论文的主要研究内容包括以下三个方面:比较了氧化石墨烯(GO)、纳米铂(Pt)、纳米金-壳聚糖(Au-CTS)分别修饰玻碳电极(GCE)后的电化学交流阻抗行为,得到氧化石墨烯(GO)的修饰效果最佳。选用它作为交联剂,当GO和DNA的吸附浓度均为5mg/m L时,DNA的吸附电位和吸附时间分别为0.50V、200s时,通过计时电流法获得的DNA/GO/GCE复合膜传感器在pH=7.00的磷酸盐缓冲溶液中(PBS)中对丙烯酰胺(AA)的响应效果最佳,以差分脉冲伏安法(DPV)为测定方法,其电化学信号大小与丙烯酰胺(AA)的浓度对数呈现良好的线性关系,响应范围为5.0×10-8~1.0×10~(-3)mol/L,线性方程为△I=4.9286+0.4245lgc,相关系数为0.9989。采用水热法制备的GO-ZnS复合纳米材料,其SEM、XRD图显示ZnS量子点均匀地掺杂到了GO中。考查了GO、ZnS、GO-ZnS分别修饰玻碳电极(GCE)后获得的DNA/GO/GCE、DNA/ZnS/GCE、DNA/GO-ZnS/GCE复合膜传感器的差分脉冲伏安行为,得到GO-ZnS复合纳米材料的修饰效果最佳。当GO-ZnS和DNA的吸附浓度分别为6mg/mL、4mg/mL时,扫描速度为50mV/s时,DNA/GO-ZnS/GCE复合膜传感器在pH=4.60的醋酸盐缓冲溶液中对Ni化合物的响应范围为5.0×10~(-7)~1.0×10~(-3)mol/L,线性方程为△I=4.8176+0.4272lgc,相关系数为0.9949。采用电化学方法,发现DNA/GO-ZnS/GCE复合膜传感器在pH=4.60的醋酸盐缓冲溶液中对AA-Ni复合体系的响应范围为1.0×10~(-7)~1.0×10~(-3)mol/L,线性方程为△I=4.5333+0.3934lgc,相关系数为0.9931。该传感器测定AA-Ni复合体系时所得的鸟嘌呤(G)的氧化峰电流变化差值(△I)略低于丙烯酰胺(AA)单一体系和Ni化合物单一体系的鸟嘌呤(G)的氧化峰电流变化差值(△I),且复合体系在pH=4.60的醋酸盐缓冲液的响应灵敏度明显高于在pH=7.00的磷酸盐缓冲溶液中(PBS)中的响应灵敏度。
[Abstract]:The author of this paper by hydrothermal method oxidation graphene ZnS quantum dots were synthesized (GO-ZnS) nano composite materials, using scanning electron microscopy (SEM), X ray diffraction (XRD) on the surface morphology and composition were analyzed, in order to obtain the GO-ZnS nanocomposite modified glassy carbon electrode (GCE), greatly improved the voltammetric response of glassy carbon electrode. A new type of biosensor was prepared to enhance the effect of electrode interface electron transfer based on GO-ZnS, realized the detection of environmental priority pollutants. The main contents of this thesis include the following three aspects: the comparison of graphene oxide (GO), nano platinum, gold nanoparticles (Pt) chitosan (Au-CTS) were modified glassy carbon electrode (GCE) electrochemical impedance behavior of the obtained graphene oxide (GO) modification effect is the best. It used as a crosslinking agent, the adsorption concentration when GO and DNA were 5mg/m L, DNA of the adsorption potential and adsorption The time was 0.50V, 200s, DNA/GO/GCE composite film sensor by chronoamperometry obtained in pH=7.00 phosphate buffer solution (PBS) of acrylamide (AA) in response to the best effect by differential pulse voltammetry (DPV) measurement methods, the electrochemical signal size and concentration of acrylamide (AA) the log shows a good linear relationship, the response range is 5 * 10-8~1.0 * 10~ (-3) mol/L, the linear equation was I=4.9286+0.4245lgc, correlation coefficient is 0.9989. using GO-ZnS nanocomposites prepared by hydrothermal method, the SEM, XRD shows ZnS quantum dots uniformly doped in GO. ZnS, GO were studied. GO-ZnS modified glassy carbon electrode (GCE) for DNA/GO/GCE, DNA/ZnS/GCE, DNA/GO-ZnS/GCE composite film sensor by differential pulse voltammetry, get the modification effect of GO-ZnS nanocomposites. The best adsorption concentration when GO-ZnS and DNA respectively. 6mg/mL, 4mg/mL, scanning speed is 50mV/s, the DNA/GO-ZnS/GCE composite film sensor in acetate buffer solution pH=4.60 in the range of Ni compounds in response to 5 * 10~ (-7) ~1.0 * 10~ (-3) mol/L, the linear equation was I=4.8176+0.4272lgc, correlation coefficient is 0.9949. by electrochemical method, DNA/GO-ZnS/GCE composite film sensor acetate buffer solution pH=4.60 in the range of AA-Ni composite response is 1 * 10~ (-7) ~1.0 * 10~ (-3) mol/L, the linear equation was I=4.5333+0.3934lgc, correlation coefficient is determined from the composite system of AA-Ni 0.9931. sensor (G) guanine oxidation peak current difference (delta I) slightly lower than acrylamide (AA) single system and Ni compound system with single guanine (G) oxidation peak current difference (delta I), and the response sensitivity in acetate buffer solution of pH=4.60 composites was significantly higher than that of Response sensitivity in the phosphate buffer solution (PBS) of pH=7.00.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X830;O657.1

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