[摘要]：The strongly enhanced and localized optical fields that occur within the gaps between metallic nanostructures can be leveraged for a wide range of functionality in nanophotonic and optical metamaterial applications Here, we introduce a means of precise control over these nanoscale gaps through the application of a molecular spacer layer that is self-assembled onto a gold film, upon which gold nanoparticles (NPs) are deposited electrostatically Simulations using a three-dimensional finite element model and measurements from single NPs confirm that the gaps formed by this process. between the NP and the gold film, are highly reproducible transducers of surface-enhanced resonant Raman scattering With a spacer layer of roughly 16 nm, all NPs exhibit a strong Raman signal that decays rapidly as the spacer layer is increased
