Photonics and Optoelectronics Group, Department of Physics and Center for NanoScience (CeNS), Ludwig Maximilian University München , Amalienstrasse 54, Munich 80799, Germany.
ACS Appl Mater Interfaces. 2014 Jun 25;6(12):8947-52. doi: 10.1021/am5023418. Epub 2014 Jun 12.
We demonstrate a strategy for surface-enhanced Raman spectroscopy (SERS) of supported lipid membranes with arrays of plasmonic nanoantennas. Colloidal lithography refined with plasma etching is used to synthesize arrays of triangular shaped gold nanoparticles. Reducing the separation distance between the triangle tips leads to plasmonic coupling and to a strong enhancement of the electromagnetic field in the nanotriangle gap. As a result, the Raman scattering intensity of molecules that are located at this plasmonic "hot-spot" can be increased by several orders of magnitude. The nanoantenna array is then embedded with a supported phospholipid membrane which is fluid at room temperature and spans the antenna gap. This configuration offers the advantage that molecules that are mobile within the bilayer membrane can enter the "hot-spot" region via diffusion and can therefore be measured by SERS without static entrapment or adsorption of the molecules to the antenna itself.
我们展示了一种利用等离子体纳米天线阵列的表面增强拉曼光谱（SERS）研究支撑脂质膜的策略。采用等离子体刻蚀精细修正胶体光刻技术合成了三角形金纳米粒子阵列。减小三角形尖端之间的分离距离会导致等离子体耦合，并使纳米三角形间隙中的电磁场得到极大增强。结果，位于这个等离子体“热点”的分子的拉曼散射强度可以提高几个数量级。然后，将纳米天线阵列嵌入到在室温下呈流体状态并跨越天线间隙的支撑磷脂膜中。这种结构具有优势，即双层膜内可移动的分子可以通过扩散进入“热点”区域，因此可以通过 SERS 进行测量，而无需分子被静态捕获或吸附到天线本身。
