基于纳米复合材料的光电化学生物传感器的研制及应用

发布时间：2018-03-10 11:44

本文选题：纳米复合材料　切入点：光电化学生物传感器　出处：《山东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：光电化学(PEC)检测是一种新开发的适用于传感检测平台的分析技术,通过将光生载流子和电化学信号相结合,以检测在光电极表面发生的化学反应变化。光电化学生物传感器已应用于生物分析、临床检测、环境保护、食品检验等诸多领域。近年来,基于纳米复合材料的PEC传感器的研制及分析取得了突破性进展。本文中,利用半导体与二维纳米材料的复合制备了新型PEC传感器,基于纳米复合材料具有大的比表面积、优异的导电性能和较高的光电转换效率,进行了以下工作内容:1.通过一种简单、有效的方法合成了WS2/CdS异质结构纳米复合材料,并成功应用于小分子的光电化学检测。首先,通过电泳沉积的方法将用水/乙醇混合溶液分散的WS2纳米片沉积在ITO电极上,随后经由简单的连续离子层吸附反应(SILAR)在WS2薄层上生长CdS纳米颗粒。基于其异质结构以及复合材料较大的比表面积、有效电荷转移等,传感器的光电性能有了实质性的增强。L-半胱氨酸作为待测的生物小分子用于PEC生物传感器的检测,其检测下限为5.29 nM;线性范围跨度较大,为0.07μM至300μM,显示出了修饰电极具有比较满意的灵敏度、选择性和的稳定性。此外,结果表明此光电传感器在实际样品分析中具有良好的抗干扰能力和令人满意的精确度,为光电生物传感器在将来各领域中的应用奠定了良好的基础。2.通过在石墨烯量子点-二氧化钛纳米管(GQDs/TiO2 NTs)复合材料的基础上连接用于识别目标分子的适配体DNA,建立了新型的超灵敏、无标记的PEC适配体传感器。在该体系中,选择氯霉素(CAP)作为目标分析物来展现光电化学适配体传感器的分析性能。抗坏血酸(AA)在可见光照射下可有效清除复合纳米材料的光生空穴,因此本体系选用它作为整个实验的电子供体。另外,与TiO2 NTs的能级相比GQDs具有较高的LUMO和HOMO能级,二者的能级构成阶梯状结构,有利于电子空穴的分离,表现为光电极的响应显著增强。氯霉素适配体通过π-π堆积作用固定在石墨烯量子点上,在最佳的条件下,光电化学适配体传感器对氯霉素的检测显示了较低的检测下限57.9 pM以及较宽的线性范围0.5 nM-100 nM,同时该适配体传感器也具备特异性、重现性和稳定性良好的性质。此光电化学检测平台为适配体传感器的构建提供了一种简单、快速、廉价的策略,并且可以广泛应用于生物样品中CAP残留的灵敏检测。
[Abstract]:Photochemical PEC-detection is a newly developed analytical technology suitable for sensor detection platform, which combines photogenerated carriers with electrochemical signals. Photochemical biosensor has been used in many fields such as biological analysis, clinical detection, environmental protection, food inspection and so on. The research and analysis of PEC sensors based on nanocomposites have made a breakthrough. In this paper, a new type of PEC sensor was prepared by using semiconductor and two-dimensional nano-materials, based on the large specific surface area of nanocomposites. With excellent conductivity and high photoelectric conversion efficiency, the following work has been done: 1. WS2/CdS heterostructure nanocomposites were synthesized by a simple and effective method, and successfully applied to photochemical detection of small molecules. The WS2 nanoparticles dispersed in water / ethanol solution were deposited on the ITO electrode by electrophoretic deposition. Then CdS nanoparticles were grown on WS2 thin layer by a simple continuous ion layer adsorption reaction (SILARR) based on its heterogeneity and the large specific surface area and effective charge transfer of the composite. The photoelectric performance of the sensor is substantially enhanced. L- cysteine is used as a biological small molecule to be measured for the detection of PEC biosensor with a detection limit of 5.29 nm. From 0.07 渭 M to 300 渭 M, it shows that the modified electrode has satisfactory sensitivity, selectivity and stability. In addition, the results show that the photoelectric sensor has good anti-interference ability and satisfactory accuracy in sample analysis. It lays a good foundation for the application of photoelectric biosensor in various fields in the future. 2. By joining the aptamer DNA to identify the target molecule on the basis of graphene quantum dot-titania nanotube / TiO2 nanotube composite material, the aptamer DNA of the target molecule is constructed. A new type of hypersensitivity, Unlabeled PEC adaptor sensors. In this system, Chloramphenicol (CAP) was selected as the target analyte to demonstrate the analytical performance of photochemical aptamer sensor. Ascorbic acid (AAA) can effectively remove the photogenerated holes of composite nanomaterials under visible light irradiation. In addition, compared with the energy level of TiO2 NTs, GQDs has higher energy levels of LUMO and HOMO, and their energy levels form a ladder structure, which is conducive to the separation of electron holes. Chloramphenicol aptamer is immobilized on graphene quantum dots by 蟺-蟺 stacking, under the optimum conditions, The detection of chloramphenicol by photochemical aptamer sensor showed a lower detection limit of 57.9 pm and a wide linear range of 0.5 nM-100 nm, and the aptamer sensor was also specific. This photochemical detection platform provides a simple, rapid and inexpensive strategy for the construction of aptamer sensors, and can be widely used in sensitive detection of CAP residues in biological samples.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.3;O657

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