Chen Jian, Tang Peng, Liu Guiqiang, Yi Zao, Liu Xiaoshan, Pan Pingping, Liu Zheng-Qi
Jiangxi Key Laboratory of Nanomaterials and Sensors, Provincial Key Laboratory of Optoelectronic and Telecommunication, College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022, Jiangxi, People's Republic of China. School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou, People's Republic of China.
Nanotechnology. 2019 Nov 15;30(46):465204. doi: 10.1088/1361-6528/ab31d8. Epub 2019 Jul 13.
Surface-enhanced Raman scattering (SERS) detection technique has gained much attention as a powerful analytical tool in recent years. Nevertheless, the attention was mainly focused on the efficient scattering platform by structuring metals themselves, leading to more complex platforms and higher costs. Herein, a new and simple strategy to prepare large-area, low-cost, high-performance SERS substrate is introduced. Ultra-thin semiconductor silicon (Si) film is used as the functional layer for the metallic nano-particles based meta-surface. During the SERS sensing process, the emergence of a Si layer is observed to provide three key contributions: (1) to produce a maximal enhancement factor (EF) ∼470% compared to that of the bare meta-surface, (2) to keep a higher spectral stability for the Raman signal, and (3) to physically interdict the contact between the metal and the molecule. Moreover, the Si film's thickness is down to the scale of an electron's Bohr radius, indicating efficient electronic oscillations for the semiconductor material under electromagnetic excitation. The charge transfer behaviors between the molecules and the Si layer and metal nano-particles can also emerge. These findings could pave new insights on the surface-enhanced spectroscopy and lead to applications for the high-performance, large-area, low-cost SERS sensing process.
近年来，表面增强拉曼散射（SERS）检测技术作为一种强大的分析工具备受关注。然而，此前的关注主要集中在通过构建金属本身来获得高效散射平台，这导致平台更为复杂且成本更高。在此，介绍一种制备大面积、低成本、高性能SERS基底的全新且简便的策略。超薄半导体硅（Si）膜被用作基于金属纳米粒子的超表面的功能层。在SERS传感过程中，观察到Si层的出现带来了三个关键作用：（1）与裸超表面相比，产生高达约470%的最大增强因子（EF）；（2）使拉曼信号保持更高的光谱稳定性；（3）从物理上阻断金属与分子之间的接触。此外，Si膜的厚度降至电子玻尔半径的尺度，这表明在电磁激发下半导体材料存在高效的电子振荡。分子与Si层以及金属纳米粒子之间的电荷转移行为也会出现。这些发现可为表面增强光谱学开辟新的思路，并推动高性能、大面积、低成本SERS传感过程的应用。
