Pieczonka Nicholas P W, Aroca Ricardo F
Materials & Surface Science Group, Faculty of Science, University of Windsor, Windsor, ON, Canada N9B 3P4.
Chem Soc Rev. 2008 May;37(5):946-54. doi: 10.1039/b709739p. Epub 2008 Feb 27.
Our main objective in this tutorial review is to provide insight into some of the questions surrounding single molecule detection (SMD) using surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS). Discovered thirty years ago, SERS is now a powerful analytical tool, strongly tied to plasmonics, a field that encompasses and profits from the optical enhancement found in nanostructures that support localized plasmon excitations. The spectrum of the single molecule carries the quantum fingerprints of the system modulated by the molecule-nanostructure interactions and the electronic resonances that may result under laser excitation. This information is embedded in vibrational band parameters. The dynamics and the molecular environment will affect the bandwidth of the observed Raman bands. In addition, the localized surface plasmon resonances (LSPR) empower the nanostructure with a number of optical properties that will also leave their mark on the observed inelastic scattering process. Therefore, controlling size, shape and the formation of the aggregation state (or fractality) of certain metallic nanostructures becomes a main task for experimental SERS/SERRS. This molecule-nanostructure coupling may, inevitably, lead to spectral fluctuations, increase photobleaching or photochemistry. An attempt is made here to guide the interpretation of this wealth of information when approaching the single molecule regime.
在本教程综述中，我们的主要目标是深入探讨一些围绕使用表面增强拉曼散射（SERS）和表面增强共振拉曼散射（SERRS）进行单分子检测（SMD）的问题。SERS于三十年前被发现，如今已成为一种强大的分析工具，与等离子体学紧密相关，等离子体学是一个包含并受益于支持局域等离子体激发的纳米结构中发现的光学增强的领域。单分子的光谱携带了由分子 - 纳米结构相互作用以及激光激发下可能产生的电子共振所调制的系统的量子指纹。这些信息嵌入在振动带参数中。动力学和分子环境会影响所观察到的拉曼带的带宽。此外，局域表面等离子体共振（LSPR）赋予纳米结构许多光学性质，这些性质也会在观察到的非弹性散射过程中留下印记。因此，控制某些金属纳米结构的尺寸、形状以及聚集态（或分形性）的形成成为SERS/SERRS实验的主要任务。这种分子 - 纳米结构耦合不可避免地可能导致光谱波动、增加光漂白或光化学现象。本文试图在进入单分子领域时指导对这些丰富信息的解读。
