Enhanced Optical Spectroscopy for single molecule detection with Plasmonic Nanopores: Challenges and Prospects

Plasmonic nanopores are a particular family of nanocavities able to engineer and confine electromagnetic fields to subwavelength volumes. In the past decade, they have enabled a large set of applications, in particular for sensing, optical trapping, and the investigation of physical and chemical phenomena at a few or single-molecule levels. This extreme sensitivity is possible thanks to the highly confined local field intensity enhancement, which depends on the geometry of plasmonic nanocavities. Indeed, suitably designed structures providing engineered local optical fields lead to enhanced optical sensing based on different phenomena such as surface enhanced Raman scattering, fluorescence, and Forster resonance energy transfer. Here, I illustrate our most recent results on plasmonic nanopores, with specific emphasis on the detection of single molecules.