Electrical characterization of plasmonic nanopores excited with light

Abstract

Due to their superior properties in single-molecule detection, plasmonic and nanopore-based sensors have attracted research interest. In recent times, they have been combined in a single device, resulting in plasmonic nanopores-based sensors. These solid-state devices featured unprecedented enhancements in single-molecule and nanoparticle detection, optical spectroscopies and trapping, control of local temperature. In this context, we have investigated two kinds of nanostructures: plasmonic nanopores and plasmonic nanoantennas, both of which were fabricated on free-standing Si3N4 membranes. As regards the nanopores, we were able to prove that their plasmonic coating enhanced their conductance when illuminated at 631 nm. On the other side, antenna-shaped nanopores (i.e., nanoantennas) were fabricated via plasmonic photochemical deposition. At this regard, we demonstrated that it was possible to fabricate nanoantennas with different internal diameters by different time of plasmon-induced photochemical deposition of metal precursors at the free tip of the nanoantenna. In conclusion, we proved that it was possible to use each nanoantenna (i.e., each decreasing internal diameter) to detect the translocation of nanoparticles with correspondingly decreasing diameters or of DNA.