The MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand.
Nanoscale. 2013 Oct 7;5(19):8945-50. doi: 10.1039/c3nr03021k. Epub 2013 Aug 20.
We report on the self-assembly of colloidal gold nanoparticles on a stretchable, elastomeric membrane, and the use of this membrane as a base substrate for far-field confocal Raman measurements. Surface-enhanced Raman scattering (SERS) enhancement for such a substrate was estimated as 10(6) to 10(7). Atomic force microscopy has been used to study the changes in nanoparticle topography when the membrane is stretched. The homogeneous strain defined by average relative motion of nanoparticles is approximately half the macroscopically-applied biaxial strain. The SERS intensity was maximized when the membrane was at rest (i.e. without stretch), and reduced as stretching was increased. Our measurements are consistent with theoretical and numerical SERS enhancements for the interstitial gap between two spheres. The data indicate that the resting gap between the spheres is 11 nm or 16 nm, using two theoretical models. This work represents progress towards particularly facile sample fabrication and in situ tuning techniques for SERS.
我们报告了胶体金纳米粒子在可拉伸弹性膜上的自组装，以及该膜作为远场共焦拉曼测量的基底衬底的用途。这种衬底的表面增强拉曼散射（SERS）增强被估计为 10(6) 到 10(7)。原子力显微镜已用于研究当膜被拉伸时纳米颗粒形貌的变化。通过纳米颗粒的平均相对运动定义的均匀应变大约是宏观施加的双轴应变的一半。当膜处于静止状态（即没有拉伸）时，SERS 强度最大，而随着拉伸的增加，强度降低。我们的测量结果与两个球体之间的间隙的理论和数值 SERS 增强一致。数据表明，使用两种理论模型，两个球体之间的静止间隙为 11nm 或 16nm。这项工作代表了在 SERS 方面特别容易进行样品制备和原位调谐技术的进展。
