SERS活性液芯光纤的制备及超灵敏检测应用

表面增强拉曼光谱 (SERS)和表面增强共振拉曼光谱 (SERRS)技术的发展使拉曼光谱在各方面的应用突飞猛进 .利用粗糙银电极、蒸镀银岛膜、金和银溶胶的自组装膜等方法制备 SERS活性基底 ,可使拉曼光谱对样品的检测浓度达到 1 0 - 7～ 1 0 - 12 mol/ L,目前可在 1 .0 n L 内检测数十个分子1～ 3] .1 997年 Nie4 ] 和 Kneipp等5] 几乎同时报道拉曼检测达到了单分子水平 .表面修饰的光纤作为传感器 ,在实时、原位或现场检测等应用领域的研究十分活跃 6～ 9] .液芯光纤作为光纤光谱研究的分支 ,以其在液体样品检测中的独特优势备受关注…

Preparation of SERS-Active Liquid Core Fiber and Its Application to the Ultrasensitive Detection

A novel ultrasensitive detection in a small volume of a low refractive index liquid via Surface enhanced Raman scattering(SERS)-active liquid core waveguide is described. The liquid core waveguide demonstrated was constructed by using the light-guiding silica capillary modified with SERS-active nanoparticles on the inner surface of the fiber wall. The Raman signal of the sample can be remarkably enhanced by the immobilized Ag nanoparticles. The laser and SERS scattering from the flowing liquid in the core possess the totally reflective waveguide model within the fiber wall. Thus, the sample dissolved in the low refractive index liquid, e.g. methanol, can be quantitatively monitored by Raman spectra in the liquid core cell and the detection limit can reach 10 -8 mol/L.