Nanoparticle Attachment on Silver Corrugated-Wire Nanoantenna for Large Increases of Surface-Enhanced Raman Scattering

Abstract

Using three-dimensional finite-difference time-domain (FDTD) simulation, we described a systematic investigation on the electric field enhancement of the silver corrugated nanowires. The enhancement factor (EF) of surface-enhanced Raman scattering (SERS) for corrugated nanowires can be markedly increased by 1 or 2 orders of magnitude as compared with the smooth nanowires. Moreover, the EF can be further increased with nanoparticle attachment on the corrugated Ag nanowires owing to the coupling between the discrete plasmon state of the nanoparticles and continuum plasmon states of the corrugated nanowire or the crossed corrugated nanowires. The surface plasmonic field distribution of Ag nanowires can be effectively controlled by the polarization of the incident light. Raman spectrum measurements show that the relatively dense corrugated nanowires exhibit a relatively high reproducibility and SERS enhancement attributed to the elimination of polarization-dependent SERS-anisotropic enhancement via the overlapping of randomly distributed Ag nanowires. Such nanostructures as potential nanoantennas offer a route to optimize plasmon coupling for designing miniaturization integration.

A comparison of SERS and MEF of rhodamine 6G on a gold substrate

“…Surface Enhanced Raman Scattering (SERS) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and` Metal Enhanced Fluorescence (MEF) [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] both exploit the electric field enhancement associated with a plasmon resonance to substantially increase the spectroscopic signal. Despite the mechanistic similarities between SERS and MEF, there are few reports of SERS and MEF on the same structures.…”

Patchy silica-coated silver nanowires as SERS substrates

“…For example, corrugated nanowires, or nanoparticle-attached corrugated nanowires, influence the enhancement factor (EF) of SERS relative to smooth nanowires. Both the experimental and simulation results show that relatively dense overlapped nanowire networks exhibit a high reproducibility and SERS enhancement owing to the formation of homogenously distributed hot spots and the interwire effect (Tian et al 2011).…”

“…Chemical contributions that can affect SERS response depend of the distinctive surface structure and/or redistribution of conduction electrons which will be manifested as an altered dielectric constant in the surface region are possible explanation to unusual enhancement effects. Theoretical and experimental work published earlier demonstrated the influence of fine geometric nanostructures on local field enhancement which is capable of improving the enhancement factor and better understanding of subtle physical mechanism of SERS (Dawson et al 2011;Tian et al 2011;Wei et al 2008). For example, corrugated nanowires, or nanoparticle-attached corrugated nanowires, influence the enhancement factor (EF) of SERS relative to smooth nanowires.…”

Fabrication of Silver Nanowires with Corrugated-Surface and Its SERS Performance

“…例如 Chen 等 [21] 利用溶剂热法成功的获得了银纳 米颗粒修饰的银纳米线结构, 对三聚氰胺的 SERS 检测 表明这种结构的 SERS 基底具有很高灵敏度和较好的重 现性. Tian [22] 及其课题组利用电化学沉积的方法得到了 波纹状银纳米线. 以 CV 作为探针分子进行 SERS 检测 表明, 这种波纹状银纳米线的增强因子比表面光滑的银 纳米线提高了至少 1 个数量级, 而且当有纳米颗粒附着 在波纹状银纳米线上时, 增强因子还可以进一步提高.…”

“…与光滑的银纳米线相比, 波纹状银纳米线作基底时的拉 曼光谱强度提高了约 5 倍. 这是由于这种带有波纹状表 面的银纳米线在其长轴表面上也具有很高的 SERS 活 性, 而不再局限于纳米线的两端, 同时, 波纹状银纳米 线与线交叉部位的光耦合作用比光滑的纳米线要强, 导 致其总体 SERS 效果明显增强 [22,24] . 另外, 由于刻蚀作 用导致的波纹状银纳米线表面积的增加也会在一定程 度上造成分子信号的增加.…”