Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea.
J Colloid Interface Sci. 2010 Feb 15;342(2):479-84. doi: 10.1016/j.jcis.2009.10.019.
In this work, we report that the adsorption and aggregation processes of Au nanoparticles on a polymer surface can be monitored by means of surface-enhanced Raman scattering (SERS) spectroscopy. Specifically, we were able to analyze the adsorption process of citrate-stabilized Au nanoparticles onto a film of poly(4-vinylpyridine) (P4VP) by taking a series of SERS spectra, during the self-assembly of Au nanoparticles onto the polymer film. In order to better analyze the SERS spectra, we separately conducted quartz crystal microbalance (QCM), UV/vis spectroscopy, and atomic force microscope (AFM) measurements. The adsorption kinetics revealed by QCM under the in situ conditions was in fair agreement with that determined by the ex situ AFM measurement. The number of Au nanoparticles adsorbed on P4VP increased almost linearly with time: 265 Au nanoparticles per 1microm(2) were adsorbed on the P4VP film after 6h of immersion. The SERS signal measured in the ex situ condition showed a more rapid increase than that of QCM; however, its increasing pattern was quite similar to that of UV/vis absorbance at longer wavelengths, suggesting that Au nanoparticles actually became agglomerated on P4VP.
在这项工作中，我们报告说，通过表面增强拉曼散射（SERS）光谱可以监测金纳米粒子在聚合物表面上的吸附和聚集过程。具体来说，我们能够通过在聚合物膜上自组装金纳米粒子的过程中，取一系列 SERS 光谱，分析柠檬酸稳定的金纳米粒子在聚 4-乙烯基吡啶（P4VP）薄膜上的吸附过程。为了更好地分析 SERS 光谱，我们分别进行了石英晶体微天平（QCM）、紫外/可见光谱和原子力显微镜（AFM）测量。原位条件下 QCM 揭示的吸附动力学与非原位 AFM 测量确定的动力学相当吻合。在 6 小时的浸泡时间内，P4VP 上吸附的金纳米粒子数量几乎呈线性增加：每 1μm(2)的 P4VP 薄膜上吸附了 265 个金纳米粒子。在非原位条件下测量的 SERS 信号的增加速度比 QCM 更快；然而，其增加模式与较长波长处的紫外/可见吸收非常相似，这表明金纳米粒子实际上在 P4VP 上发生了聚集。
