Next Article in Journal
Mesoporous Acidic Catalysts Synthesis from Dual-Stage and Rising Co-Current Gasification Char: Application for FAME Production from Waste Cooking Oil
Previous Article in Journal
Physical Modeling of Cross Wedge Rolling Limitations
Previous Article in Special Issue
Under-Etched Plasmonic Disks on Indium Tin Oxide for Enhanced Refractive Index Sensing on a Combined Electrochemical and Optical Platform
Open AccessArticle

Enhancing the Sensitivity of Nanoplasmonic Thin Films for Ethanol Vapor Detection

Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
*
Author to whom correspondence should be addressed.
Materials 2020, 13(4), 870; https://doi.org/10.3390/ma13040870 (registering DOI)
Received: 16 January 2020 / Revised: 30 January 2020 / Accepted: 13 February 2020 / Published: 14 February 2020
(This article belongs to the Special Issue Thin Films for Sensing Applications)
Nanoplasmonic thin films, composed of noble metal nanoparticles (gold) embedded in an oxide matrix, have been a subject of considerable interest for Localized Surface Plasmon Resonance (LSPR) sensing. Ethanol is one of the promising materials for fuel cells, and there is an urgent need of a new generation of safe optical sensors for its detection. In this work, we propose the development of sensitive plasmonic platforms to detect molecular analytes (ethanol) through changes of the LSPR band. The thin films were deposited by sputtering followed by a heat treatment to promote the growth of the gold nanoparticles. To enhance the sensitivity of the thin films and the signal-to-noise ratio (SNR) of the transmittance–LSPR sensing system, physical plasma etching was used, resulting in a six-fold increase of the exposed gold nanoparticle area. The transmittance signal at the LSPR peak position increased nine-fold after plasma treatment, and the quality of the signal increased six times (SNR up to 16.5). The optimized thin films seem to be promising candidates to be used for ethanol vapor detection. This conclusion is based not only on the current sensitivity response but also on its enhancement resulting from the optimization routines of thin films’ architectures, which are still under investigation.
Keywords: thin films; gold nanoparticles; titanium dioxide; sputtering; plasma etching; plasmonic sensing; optical transmittance change; optical signal quality thin films; gold nanoparticles; titanium dioxide; sputtering; plasma etching; plasmonic sensing; optical transmittance change; optical signal quality
MDPI and ACS Style

Rodrigues, M.S.; Borges, J.; Vaz, F. Enhancing the Sensitivity of Nanoplasmonic Thin Films for Ethanol Vapor Detection. Materials 2020, 13, 870.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop