Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan.
J Colloid Interface Sci. 2011 Jun 15;358(2):384-91. doi: 10.1016/j.jcis.2011.03.032. Epub 2011 Mar 15.
Micro/nano-lithographic techniques are usually employed as a straightforward process for roughening a thin-film Au surface for surface-enhanced Raman scattering (SERS). However, a topographical pattern with deepened edges is difficult to control in a rapid and environmental-friendly way. In this study, a simple physical procedure is proposed for tailoring a thin-film Au surface with triangular nanostructures using nano-indentation technique. The as-fabricated nano-indented cavities on Au (nAu) were structured as a characterization substrate for SERS. By calculating the geometries of nAu and the increase of surface area as a function of the concentration of chemically adsorbed 2-nitro-5-thiobenzoic acid (NTB), a combined chemical and electromagnetic effect was estimated. Particularly-made nAu was adjusted for examining chemically adsorbed NTB molecules with differently intensified Raman-active groups by tuning the indentation depth and the tip-to-tip displacement. SERS enhancement factor on a specific NTB/nAu could be increased to 2.1×10(6).
微纳光刻技术通常被用作一种简单的方法来粗糙化薄膜金表面，以用于表面增强拉曼散射（SERS）。然而，以快速且环保的方式控制具有加深边缘的形貌图案是很困难的。在这项研究中，提出了一种简单的物理程序，使用纳米压痕技术在薄膜金表面上形成具有三角形纳米结构的图案。所制备的纳米压痕金（nAu）腔作为 SERS 的特征化衬底。通过计算 nAu 的几何形状和表面积的增加作为化学吸附的 2-硝基-5-巯基苯甲酸（NTB）浓度的函数，评估了化学吸附和电磁增强的联合作用。特别制作的 nAu 通过调节压痕深度和针尖间距，调整了对具有不同增强的拉曼活性基团的化学吸附的 NTB 分子的检测。在特定的 NTB/nAu 上的 SERS 增强因子可以增加到 2.1×10(6)。
