银纳米线/MoO3-X复合基底的合成及其SERS性能研究

Synthesis of Ag NW/MoO3-X composites and investigation on their SERS performance

表面增强拉曼散射(SERS)具备单分子检测能力和较高的分辨率,因此受到了广泛的关注和研究.本文首先利用氧化钼(MoO3-X)的还原特性,在不使用任何表面活性剂的条件下,以AgNO3溶液作为合成银纳米线(AgNW)的银源,通过紫外光催化,在MoO3-X薄膜表面还原获得具有交错重叠结构的AgNW.为评价合成的AgNW/MoO3-X复合基底的SERS特性,以罗丹明B作为拉曼标记物进行拉曼信号测量.结果显示,制备的AgNW/MoO3-X复合结构在电磁增强和化学增强的双重作用下,具有较好的SERS特性,表现出较宽的检测范围和灵敏度.

Surface-enhanced Raman scattering(SERS) has been widely investigated due to its single molecular fingerprint recognition and high specificity. Although tremendous achievements on the Raman signal enhancement have been made, researches on further improving the enhancement factor are still going on. In this work, we report a green fabrication of novel SERS substrate based on Ag nanowire(NW)/molybdenum sub-oxide(MoO3-X) composites. MoO3-X is first synthesized using hydrothermal method, and then is spin-coated on the glass as the first layer of the substrate. Next, AgNO3 without any other surfactant are dropped on the MoO3-X film as the Ag source to prepare Ag NW. With the help of reducing capability of theMoO3-X, under the ultra violet light irradiation, the Ag+ can be reduced to Ag0. Scan electron microscopy investigation reveals that the interlaced Ag NW are successfully produced on the MoO3-X film surface. Furthermore, by using the Rhodamine B as the Raman reporter, the Raman signals on the prepared Ag NW/MoO3-Xcomposites are detected. Results show significantly improved Raman signal intensity due to the joint electromagnetic enhancement and chemical enhancement. The above methods are expected to provide a handy way of preparing superior SERS substrate for potential usage in low-trace molecule sensing.