1. DNA-Templated Ultracompact Optical Antennas for Unidirectional Single-Molecule Emission
- Author
-
Zhu, Fangjia, Sanz-Paz, María, Fernández-Domínguez, Antonio I., Zhuo, Xiaolu, Liz-Marzán, Luis M., Stefani, Fernando D., Pilo-Pais, Mauricio, and Acuna, Guillermo P.
- Subjects
Mechanical Engineering ,Nanotechnology ,General Materials Science ,Bioengineering ,DNA ,Gold ,General Chemistry ,Condensed Matter Physics ,Fluorescent Dyes ,Nanostructures - Abstract
Optical antennas are nanostructures designed to manipulate light-matter interactions by interfacing propagating light with localized optical fields. In recent years, numerous devices have been realized to efficiently tailor the absorption and/or emission rates of fluorophores. By contrast, modifying the spatial characteristics of their radiation fields remains challenging. Successful phased array nanoantenna designs have required the organization of several elements over a footprint comparable to the operating wavelength. Here, we report unidirectional emission of a single fluorophore using an ultracompact optical antenna. The design consists of two side-by-side gold nanorods self-assembled via DNA origami, which also controls the positioning of the single-fluorophore. Our results show that when a single fluorescent molecule is positioned at the tip of one nanorod and emits at a frequency capable of driving the antenna in the antiphase mode, unidirectional emission with a forward to backward ratio of up to 9.9 dB can be achieved.
- Published
- 2022