基于金针纳米阵列的三维SERS基底的构筑及对肿瘤坏死因子-α的痕量检测

Tumor necrosis factor-α (TNF-α) is the most important indicator for diagnosis and prognosis of variety of diseases, such as cancer and infectious diseases. The current used techniques are complicated and time consuming, and the test results are easily affected by the many factors. However, surface-enhanced Raman scattering detection technique is easily manipulated, highly sensitive and highly reproducible. In addition, it can detect a variety of molecules. In this project, the ordered Au needle nanoarrays and Au nanoparticles will be prepared through the template method and liquid phase method, respectively. Based on the interaction between TNF-α and the fragments of TNF-α antibody, TNF-α will bridge the ordered Au needle nanoarrays modified by the fragments of TNF-α antibody and Au nanoparticles modified by the same antibody fragments, and finally make up three-dimensional SERS substrates with high activity. The ordered Au needle nanoarrays can make the distribution of hot spots more uniform, enhancing Raman signal homogeneity and repeatability; the modification of TNF-α antibody fragments decreases the distance between the Au needle nanoarrays and Au nanoparticles, improving the detection sensitivity. We plan to conduct a series of experiments to explore the new way for detecting TNF-α. First, the controllable preparation of the Au needle nanoarrays and Au nanoparticles will be conducted and the SERS activity will be also optimized. Second, we will study the adsorption of the Raman reporter and TNF-α antibody fragments on the surface of Au nanoparticles and Au needle nanoarrays. Third, the SERS substrates will be evaluated based on the specific recognition of TNF-α, and the quantitative relationship of TNF-α concentration with the Raman signal will be established. This project will provide a new scientific way for measurement of TNF-α and many other molecules, such as ILs. This technique is the rapid, convenient and effective way in clinic application.

肿瘤坏死因子-α（TNF-α）对于多种疾病（如肿瘤、感染）的诊断及预后有重要意义。当前TNF-α检测技术操作步骤繁杂、检测结果易受环境影响。表面增强拉曼散射（SERS）光谱技术操作简便、灵敏度和重复性高，可检测多种分子。本项目分别以模板法、液相法制备结构可控的有序金针纳米阵列及金纳米颗粒；基于TNF-α与抗体片段的结合，以TNF-α为桥梁连接抗体片段修饰后的金针阵列和纳米颗粒，构筑三维SERS基底，实现TNF-α的痕量检测。有序金针阵列使热点分布均匀，确保了拉曼信号的均匀性、重复性；抗体片段实现了阵列与纳米颗粒的小间隙耦合，提升了基底的SERS活性。研究金纳米颗粒和阵列的可控制备，优化其SERS活性；研究探针分子和抗体片段的吸附规律；探究基底对TNF-α的特异性识别能力，揭示TNF-α浓度和拉曼信号的定量关系。项目的实施为TNF-α等分子的检测提供材料基础和科学依据，为临床应用奠定基础。

肿瘤坏死因子-α(tumor necrosis factor,TNF-α)主要是介导抗肿瘤和调节机体免疫功能，参与炎症病变的多方面病理变化。血清中TNF-α的含量检测有助于疾病诊断和预后。TNF-α快速痕量检测是研究TNF-α与恶性肿瘤相互作用的基本问题之一，该检测能够指导多种疾病的治疗及预后。目前TNF-α检测技术操作步骤繁杂、检测结果易受环境影响。. 表面增强拉曼光谱（SERS）技术操作简便、信号灵敏度和重复性高。本项目制备了结构可控的金针纳米阵列及金纳米颗粒，基于TNF-α与抗体的特异性结合，以TNF-α为桥梁连接抗体修饰后的金针阵列和纳米颗粒，构筑三维SERS基底，实现了TNF-α的痕量检测。主要研究内容与结果：. 1、通过改变氧化电压、腐蚀时间等参数，制备了具有锥状孔的二维氧化铝模板，孔径分别为90nm、200nm和400nm。在此基础上，通过改变镀膜的电流数值和时间得到了不同间隙的金膜阵列。以罗丹明6G为拉曼信号报告分子，研究了金膜阵列的拉曼信号增强效果，90nm孔径镀膜9分钟的金膜阵列具有最高增强效应。. 2、研究了Hela和U251细胞在氧化铝模板表面的迁移和增殖行为，Hela细胞在孔径40-70nm模板表面有较强迁移行为，U251细胞在平均孔径120nm模板表面有较好的突触生长。. 3、制备了球状和八面体状金纳米颗粒，将对巯基苯甲酸与金纳米颗粒溶液混合进行信号分子标记。采用改性聚乙二醇表面修饰，使金纳米颗粒表面带羧基，避免团聚。将抗体与羧基偶联，最终获得了抗体、巯基苯甲酸共同修饰的复合金纳米颗粒。. 4、基于金膜阵列和抗体修饰后的金纳米颗粒，研究了检测TNF-α的三维基底的构建方法，形成了夹心免疫式SERS增强基底，检测信号特征峰强度与TNF-α浓度的对数呈线性关系，相关系数为0.98。. 5、讨论了SnPc在Cu（111）和Au（111）面的基态几何结构，结合能及扩散势垒；讨论了平面内双轴拉伸对ZrSe2的热电性能的影响；结合玻尔兹曼方程与形变势理论讨论了PdSe2热输运系数晶格热导率、载流子迁移率。. 发表学术论文5篇，申报发明专利1项。