Design of plasmonic antennas based on improved nanocylinder dimers by controlled gold deposition for biodetection applications

IVÁN A. RAMOS; L. M. LEÓN HILARIO; M. L. PEDANO; A. A. REYNOSO

Montevideo

Congreso; VIII Congreso Nacional de Sólidos y Primer Encuentro Bi-Nacional (Argentina-Uruguay).; 2019

Facultad de Ingeniería de la Universidad de la República.

In recent years, several advanced methods of fabricating structures of the order ofnanometers have been developed. In particular, the manufacture of gapped metalliccylinders using on-wire lithography (OWL) [1]. This technique allows control of thechemical composition and architecture of a one-dimensional wire from thenanometer to micrometer length scale [2]. This ability enables the exploration of avariety of chemical and physical phenomena, including plasmon coupling andelectromagnetic field enhancement in a very unique manner [3], and it hasmotivated several studies in order to understand the behavior of the increase of theelectric field as a function of the wavelength and geometric parameters. Theparticular study of the electric enhancement localized in the gap has been carry onby Qin et al. [3] for nanodisk with length between 40 to 400 nm. Furthermore, theperiodicity of this electric field increase for longer cylinder, until 2000 nm, has beenstudied by Pedano et al. [4] and Li et al. [3].This work proposed modified nanoantennas based on gold nanocylinder dimers (ornanorods) with gold deposited on the cylinders in the area far from the gap. Theenhancement factor (EF) is calculated using the method of discrete dipoles (DDA)[5] in order to simulate the electromagnetic field near the gap. This study assumes aconstant incident field of wavelength 633 nm from a Helium-Neon laser