利用AAO模板制备SERS基底检测SudanⅠ

The SERS Detection of SudanⅠby Using AAO as Template to Prepare the Substrate

通过模板法制备大面积、可控的、可重复的、热点集中的金纳米结构阵列,并在纳米结构阵列上通过化学修饰分子,吸附更多苏丹红Ⅰ分子至金纳米的SERS增强区域,实现其高灵敏的表面增强拉曼分析检测。以多孔阳极氧化铝为模板,通过真空蒸镀金,约200nm厚度,复制氧化铝的孔洞结构,用碱液将氧化铝模板腐蚀去除,可得到氧化铝模板的互补结构,即大面积的、均匀的金半球纳米结构阵列。在金纳米结构阵列上修饰十二硫醇,硫醇巯基端与纳米金相结合,碳链端自组装形成非极性的疏水环境,疏水环境可以捕获苏丹红Ⅰ分子,使其吸附至纳米金结构表面的SERS增强区域,实现苏丹红Ⅰ的SERS检测。由于SERS基底表面的金半球纳米结构均匀、规整,在激光光斑的区域内,苏丹红Ⅰ的SERS信号均匀、稳定,可以对苏丹红Ⅰ进行定量分析。苏丹红Ⅰ的拉曼峰强度对数与浓度对数之间呈线性关系,线性相关系数达0.99,线性范围为5×10-4-10-7 mol·L-1,回收率范围77%-117%。此方法的检测限可达到4×10-8 mol·L-1,与国标的高效液相色谱的检测限相当。

The large-scale controllable,ordered two-dimensional arrays of gold nanostructure with hot-spot were prepared together with chemical molecules were modified on the surface to concentrate SudanⅠ within the zone of the SERS effect,which lead to analytical detection of SudanⅠ in high resolution.The vapor of gold was deposed on anodic aluminum oxide（AAO）template by-200nm thickness to replicate its nanochannels,and the negative structure i.e.large-scale ordered gold nano-hemisphere array,was obtained after the removal of the template of AAO by NaOH solution.Au nano-hemisphere array was modified by 1-Dodecanethiol which can be self-assembled monolayer on the surface and concentrate SudanⅠ within the zone of the SERS detection,which can facilitate the measurement of SudanⅠ.Due to the order and regularity of Au nano-hemisphere array,the signal of SudanⅠ in the range of laser illumination is stable and uniform,and the quantitative analysis of SudanⅠ was realized.The SERS intensity of SudanⅠ is logistic proportional to the concentration in the range of 10-7 to 5×10-4 mol·L-1.The corresponding correlation coefficient of the liner equation is 0.99,the recoveries of SudanⅠ are between 77%-117%.The limit of detection for SudanⅠ is 4×10-8 mol·L-1,comparable to that of HPLC of Chinese national standard method.