Nanopore formation on Au coated pyramid under electron beam irradiations (plasmonic nanopore on pyramid)

There have been tremendous interests about the single molecule analysis using a sold-state nanopore. The solid-state nanopore can be fabricated either by drilling technique, or diffusion technique by using electron beam irradiations. The solid-state SiN nanopore device with electrical detection technique recently fabricated, however, the solid-state Au nanopore with optical detection technique can be better utilized as the next generation single molecule sensor. In this report, the nanometer size openings with its size less than 10 nm on the diffused membrane on the 200 nm Au pyramid were fabricated by using field emission scanning electron microscopy (FESEM) electron beam irradiations, transmission electron microscopy (TEM), etc. After the sample was being kept under a room environment for several months, several Au (111) clusters with ~ 6 nm diameter formed via Ostwald ripening are observed using a high resolution TEM imaging. The nanopore with Au nanoclusters on the diffused membrane can be utilized as an optical nanopore device.

Graphical abstractThis image presents an Au (111) particle formed on the electron induced membrane inside an Au aperture. The Au aperture was drilled on the apex of the pyramid. An Au nanoparticle with a ~ 6 nm diameter is shown at the center surrounded by electron beam induced membrane (c), at the top of pyramid (b), inserted in the pyramidal array (a).A pyramidal array and a single pyramid are shown as a large background image (a) and (b) (middle, b). A diffused pore membrane under electron beam irradiation is shown with a 200 nm thick Au (black) and an electron beam induced membrane (gray) in (c), and a 6 nm diameter Au nanoparticle with a (111) lattice is presented at the center.Figure optionsDownload full-size imageDownload as PowerPoint slide