表面等离子体受激辐射放大领结型纳米天线的SERS单分子探测(英文)

Single Molecule Detection by SERS of a Spaser-Based Bowtie Nanoantenna

基于表面等离激子受激辐射放大原理,提出了一种应用于表面增强拉曼散射(SERS)单分子探测的领结型纳米天线结构。采用有限元方法(FEM)研究其局域表面等离子体共振(LSPR)和SERS特性。结果表明,该领结型纳米天线的局域表面等离子体共振强度和局域电场强度得到明显的增强,其散射截面为非表面等离激子受激辐射放大领结型纳米天线的1.1×104倍,局域电场强度为1×102倍。同时,该领结型纳米天线的表面增强拉曼散射增强因子最大达到1016,足以进行精确的单分子探测;整个纳米天线表面的增强因子也可达到1012,足以应用于单个生物分子的探测。

Based on the mechanism of the surface plasmon amplification by stimulated emissions of radiation（spaser）,a bowtie nanoantenna structure is proposed for single molecule detection by surface enhanced Raman scattering（SERS）.The localized surface plasmon resonance（LSPR）properties and the SERS characteristics of the bowtie nanoantenna are numerically analyzed by the finite element method（FEM）.The results show that the LSPR strength and the local electric field intensity of the bowtie nanoantenna can be greatly amplified,and its scattering cross-section and electric field strength are up to 1.1×104 and 1×102 times of the non-spaser bowtie nanoantenna,respectively.Meantime,the maximum SERS enhancement factor is 1016 generated by the bowtie nanoantenna,which is enough to accurately detect a single molecule.Moreover,there is a higher SERS enhancement factor of 1012 on the entire surface of the nanoantenna,which is also sufficient for single bio-molecular detection.