Abstract: Surface enhanced Raman spectroscopy (SERS) is a technique widely used in detecting analytes at low concentrations and could provide structural information at the sametime. It is necessary to find the optimal particle size, shape and spatial distribution to optimize the SERS substrate. Current research efforts are focused on fabricating new kind of nanocomposite using as SERS substrates. Porous materials have long been employed as SERS substrate because of their unique features, the porosity that enable them as efficient adsorbents for target molecule. The porous α⁃Fe2O3 was used as solid support. In this paper, porous nano α⁃Fe2O3 was synthesized by hydrothermal method using porous α⁃Fe2O3 as solid carrier, and then calcined into Fe, so that there were porous channels on the surface of Fe. PATP aqueous solution and melamine aqueous solution were used as probe molecules. By adjusting the size of Au nanoparticles and investigating its influence on SERS performance, the optimum performance of 50 nm Au was obtained.The structures and compositions of the nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X⁃ray diffraction (XRD), and N2 adsorption. Our research illustrates a new kind of porous Fe2O3⁃Ag nanocomposite, that could be used as effective SERS substrate to adsorb and detect trace level of target analyte.

Key words: Porous nanocomposite, Au nanoparticles, Surface enhanced Raman spectroscopy (SERS), Substrate, SERS activity

摘要： 表面增强拉曼散射光谱(SERS)是一种广泛应用于低浓度分子物种识别并且能够提供结构信息的技术。SERS检测中基底纳米材料的颗粒大小、形状和空间分布对检测结果有着重要影响。探索制备新型纳米结构可以为SERS研究和应用提供新的活性基底和理论基础。由于具有良好的传质和吸附性能，多孔材料广泛应用于构筑SERS活性基底纳米复合物。以多孔磁性纳米材料作固相载体，通过水热合成多孔纳米α⁃Fe2O3，再将其还原成Fe，使Fe的表面也有孔道存在。在Fe表面自组装Au纳米材料构筑SERS基底，以对巯基苯胺（PATP）和三聚氰胺水溶液作为目标分子，对其SERS性能进行测试。调控Au纳米粒子尺寸大小，考察其对SERS性能影响，得到50 nm Au具有最优性能。利用扫描电子显微镜（SEM）、X 射线衍射(XRD)和N2吸附等表征手段，对纳米复合物结构及组成进行分析表征。结果表明，得到了一种同时具有吸附和检测效果的纳米复合物SERS基底。

关键词: 多孔材料, 　金纳米粒子, 　表面增强拉曼光谱, 　基底, 　SERS性能