Yu Qiuming, Golden Greg
Department of Chemical Engineering, Center for Nanotechnology, University of Washington, Seattle, Washington 98195, USA.
Langmuir. 2007 Aug 14;23(17):8659-62. doi: 10.1021/la7007073. Epub 2007 Jul 13.
In this work, surface-enhanced Raman scattering (SERS) was applied to probe the orientation of cytochrome c (Cyt-c) on gold nanohole arrays functionalized with self-assembled monolayers (SAMs) of alkane thiols with positively (-NH2) and negatively (-COOH) charged terminal groups. Square grid gold nanohole arrays with a nanohole diameter of 270 nm and a grating of 350 nm were fabricated by electron beam lithography (EBL) and were used as the SERS substrates. The SERS intensities of the nontotally symmetric mode (B(1g) mode nu(11)) and the totally symmetric mode (A(1g) mode nu(4)) and their ratios were used to determine the orientation of Cyt-c on surfaces. The results indicate that the heme group is close and perpendicular to the negatively charged surface but is far from and oriented at an angle to the positively charged surface. Cyt-c has a random or more flat orientation on the bare Au nanoholes surface.
在这项工作中，表面增强拉曼散射（SERS）被用于探测细胞色素c（Cyt-c）在由带有正电荷（-NH2）和负电荷（-COOH）端基的烷硫醇自组装单分子层（SAMs）功能化的金纳米孔阵列上的取向。通过电子束光刻（EBL）制备了纳米孔直径为270 nm且光栅为350 nm的方形网格金纳米孔阵列，并将其用作SERS基底。利用非全对称模式（B(1g)模式ν(11)）和全对称模式（A(1g)模式ν(4)）的SERS强度及其比值来确定Cyt-c在表面上的取向。结果表明，血红素基团靠近并垂直于带负电荷的表面，但远离带正电荷的表面且与该表面呈一定角度取向。Cyt-c在裸露的金纳米孔表面具有随机或更平坦的取向。
