Overcoming evanescent field decay using 3D-tapered nanocavities for on-chip targeted molecular analysis.

ABSTRACT: Enhancement of optical emission on plasmonic nanostructures is intrinsically limited by the distance between the emitter and nanostructure surface, owing to a tightly-confined and exponentially-decaying electromagnetic field. This fundamental limitation prevents efficient application of plasmonic fluorescence enhancement for diversely-sized molecular assemblies. We demonstrate a three-dimensionally-tapered gap plasmon nanocavity that overcomes this fundamental limitation through near-homogeneous yet powerful volumetric confinement of electromagnetic field inside an open-access nanotip. The 3D-tapered device provides fluorescence enhancement factors close to 2200 uniformly for various molecular assemblies ranging from few angstroms to 20 nanometers in size. Furthermore, our nanostructure al

SUBMITTER: Kumar S 

PROVIDER: S-EPMC7287113 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature