An inverted honeycomb plasmonic lattice as an efficient refractive index sensor
Rodríguez-Álvarez, Javier (Institut Català de Nanociència i Nanotecnologia)
Gnoatto, Lorenzo (Universitat de Barcelona. Departament de Física de la Matèria Condensada)
Martínez-Castells, Marc (Universitat de Barcelona. Departament de Física de la Matèria Condensada)
Guerrero, Albert (Institut de Microelectrònica de Barcelona)
Borrisé, Xavier (Institut Català de Nanociència i Nanotecnologia)
Fraile Rodríguez, Arantxa (Institut Català de Nanociència i Nanotecnologia)
Batlle, Xavier (Institut Català de Nanociència i Nanotecnologia)
Labarta, Amílcar (Institut Català de Nanociència i Nanotecnologia)

Date:	2021
Abstract:	We present an efficient refractive index sensor consisting of a heterostructure that contains an Au inverted honeycomb lattice as a main sensing element. Our design aims at maximizing the out-of-plane near-field distributions of the collective modes of the lattice mapping the sensor surroundings. These modes are further enhanced by a patterned SiO layer with the same inverted honeycomb lattice, an SiO spacer, and an Au mirror underneath the Au sensing layer that contribute to achieving a high performance. The optical response of the heterostructure was studied by numerical simulation. The results corresponding to one of the collective modes showed high sensitivity values ranging from 99 to 395 nm/RIU for relatively thin layers of test materials within 50 and 200 nm. In addition, the figure of merit of the sensor detecting slight changes of the refractive index of a water medium at a fixed wavelength was as high as 199 RIU -1. As an experimental proof of concept, the heterostructure was manufactured by a simple method based on electron beam lithography and the measured optical response reproduces the simulations. This work paves the way for improving both the sensitivity of plasmonic sensors and the signal of some enhanced surface spectroscopies.
Grants:	Agencia Estatal de Investigación PGC2018-097789-B-I00
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Au plasmonic nanostructures ; Inverted honeycomb lattice ; Surface lattice resonances ; Refractive index sensor
Published in:	Nanomaterials, Vol. 11, issue 5 (May 2021) , art. 1217, ISSN 2079-4991

DOI: 10.3390/nano11051217
PMID: 34064520

12 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles