This study presents the fabrication and characterization of imine-functionalized Au nanoparticle (Au NP) film using Poly (ethyleneimine) (PEI) as a reducing and surface stabilizing reagent. The PEI-capped Au NPs can be self-assembled at the water-hexane interface by adding alcohol containing alkanethiol. Furthermore, large-area film made from PEI and alkanethiol-capped Au NPs is produced on a glass substrate with varying interparticle distances that can be controlled by the alkyl chain lengths, ranging from C2 (ethanethiol), C4 (1-butnaethiol), C6 (1-hexanethiol), C8 (1-octanethiol), to C10 (1-decanethiol) at the water-hexane interface. These 2D films show strong collective localized surface plasmon resonance (LSPR) extinction bands that are tunable via near-field coupling of adjacent Au NPs. Pronounced chain-length-dependent red shifts of the SPR bands have been observed for the PEI-capped Au films. The obtained PEI-capped Au films exhibit distinct interparticle-distance-dependent SERS characteristics.

这项研究介绍了亚胺官能化的金纳米粒子（Au NP）膜的制备和表征，该膜使用聚（乙烯亚胺）（PEI）作为还原剂和表面稳定剂。通过添加含链烷硫醇的醇，PEI封端的Au NP可以在水-己烷界面处自组装。此外，在玻璃基板上生产了由PEI和烷硫醇封端的Au NPs制成的大面积薄膜，其颗粒间距离可以通过烷基链长控制，C2（乙硫醇），C4（1-丁硫醇），C6 （1-己硫醇），C8（1-辛硫醇）至C10（1-癸硫醇）在水-己烷界面处形成。这些2D胶片显示出强大的集体局部表面等离子体共振（LSPR）消光带，该消光带可通过相邻Au NP的近场耦合来调节。对于PEI封端的Au膜，已经观察到SPR带的明显的链长依赖性红移。获得的PEI覆盖的Au膜表现出独特的颗粒间距离依赖性SERS特性。