树形高分子修饰银纳米立方体作为分子捕获器用于表面增强拉曼散射检测应用的研究

项目名称： 树形高分子修饰银纳米立方体作为分子捕获器用于表面增强拉曼散射检测应用的研究

项目编号： No.21207038

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 环境化学

项目作者： 张强

作者单位： 华东师范大学

项目金额： 26万元

中文摘要： 表面增强拉曼散射（SERS）光谱拥有超高的检测灵敏度和物质结构辨析能力，是近年来受到广泛关注的检测技术之一。SERS检测技术要求检测物质吸附在金属表面附近数纳米的距离范围之内，检测物质才会产生显著的SERS增强效应，而大多数化学分子和金属表面之间不存在较强的物理、化学相互作用，因此很难稳定地吸附在金属表面，其结果降低了SERS检测技术的灵敏度，限制了SERS检测物质范围。 针对上述问题，我们设计一款拉曼散射增强型的分子捕获器，即在银纳米立方体表面修饰树形高分子，利用它和检测物质之间的疏水、静电相互作用以及共价连接的方式将检测物质有效地捕获到金属表面附近，从而提高SERS检测技术的灵敏度，扩大SERS检测物质的范围，推动SERS在检测领域的应用发展。

中文关键词： 表面增强拉曼散射；凹面银纳米颗粒；胶体溶液；光谱波动；

英文摘要： Surface Enhanced Raman Scattering (SERS) spectroscopy has been developed into an ultrasensitive and ultra-rapid analytical technique, which allows the detection limit can be down to single molecular level. The high sensitivity of SERS requires analytes to be close contact with the plasmonic metal surface; otherwise, the SERS signal strength will decrease rapidly. However, there are a large number of analytes with small SERS cross-sections and low affinity to the plasmonic metal surface, which extremely hinders their detection by the means of SERS. Thus, to design efficient and flexible metal substrates has been one of the key challenges for SERS detection. In this project, we will develop a molecular trapper for SERS detection based on silver nanocubes, which have been demonstrated to be an excellent plasmonic nanostructure for SERS detection. The PAMAM dendrimer with cystamine core is employed here to modify the silver nanocubes, and play a critical role of trapping analytes close to the metal surface through the mechanism of hydrophobic interactions, electrostatic interactions and covalent bonds. With the use of this molecular trapper, the intensity of molecular SERS signals can be highly enhanced, and a wider variety of chemicals can be analysed by using SERS detection.

英文关键词： surface-enhanced Raman scattering；concave silver nanoparticles；colloidal solution；spectral intensity fluctuation；