The Effect of Silver Grating and Nanoparticles Grafting for LSP-SPP Coupling and SERS Response Intensification
The Effect of Silver Grating and Nanoparticles Grafting for LSP-SPP Coupling and SERS Response Intensification
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DOI：
10.1021/acs.jpcc.6b01587
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发表时间：
2016-05-19
影响因子：
3.7
通讯作者：
Lyutakov, O.
中科院分区：
文献类型：
--
作者：
Kalachyova, Y.;Mares, D.;Lyutakov, O.
系统的研究与金和银纳米粒子（MeNPs）的各种形状和介电功能固定到银光栅的结构进行。该结构可以用作双共振Sers（表面增强拉曼光谱）系统，其具有由银光栅支撑的表面等离子体激元（SPP）和在接枝的金属纳米颗粒（MeNPs）上激发的局部表面等离子体激元（LSP）之间的耦合。银光栅支持在785 nm波长照明下的SPP激发。制备并使用球形银和金纳米颗粒、三角形银纳米棱柱和金纳米棒，目的是逐渐覆盖400-850 nm波长范围内的LSP激发。MeNP通过4，4 '-联苯二硫醇（BFDT）接头接枝。罗丹明6 G（R6 G）分子被添加到Sers基底上并位于MeNP上方和之间。几个波长（470，532和785 nm）被应用于探测Sers响应。根据纳米颗粒类型和激发波长，R6 G或BFDT分子产生显著Sers信号。利用时域有限差分法（FDTD）对所制备的结构的特性进行了模拟。测量和模拟的Sers数据是在合理的协议，测量值低于那些计算。
The systematic study of structures with gold and silver nanoparticles (MeNPs) of various shapes and dielectric functions immobilized onto the silver grating is performed. The structures may serve as double resonance SERS (surface-enhanced Raman spectroscopy) systems with coupling between surface plasmon polariton (SPP) supported by the silver grating and localized surface plasmons (LSPs) excited on the grafted metal nanoparticles (MeNPs). The silver grating supports SPP excitation under the 785 nm wavelength illumination. Spherical silver and gold nanoparticles, triangular silver nanoprisms and gold nanorods are prepared and used with the aim to gradually cover the LSP excitation in the 400-850 nm wavelength range. MeNPs are grafted through the 4,4'-biphenyldithiol (BFDT) linkers. Rhodamine 6G (R6G) molecules are added onto SERS substrates and located above and between the MeNPs. Several wavelengths (470, 532, and 785 nm) are applied to probe the SERS response. Depending on the nanoparticles type and excitation wavelength a significant SERS signal is produced by R6G or BFDT molecules. Properties of the prepared structures are simulated using the Finite-difference time-domain method (FDTD). The measured and simulated SERS data are in reasonable agreement, the measured values being lower than those calculated.