Optimisation of the Detection Sensitivity of Plasmonic Nanoantenna Based Sensors for Mid-infrared Spectroscopy. (2015)

• Record Type: Journal Article
• Authors: De Marcellis, A.; Palange, E.; Janneh, M.; Rizza, C.; Ciattoni, A.; Mengali, S.
• Is Part Of: Procedia engineering. Volume 120(2015)
• Page Start: 1179
• Page End: 1182
• Publication Date: 2015
• Subjects: SEIRA -- Metamaterials -- Metasurfaces -- Nanoantennas.; Engineering -- Congresses; Engineering -- Periodicals; Engineering; Conference proceedings; Periodicals; 620.005
• DOI: 10.1016/j.proeng.2015.08.779
• Languages: English
• ISSNs: 1877-7058

Abstract

Abstract: In this paper we report on the optimisation of the optical characteristics of 2D-arrays of plasmonic gold nanoantennas (NA) that can be used as high sensitivity mid-infrared spectroscopic sensor for the detection of chemical/biological substances by using the Surface Enhanced Infrared Absorption (SEIRA) technique. This approach allows to detect the presence of a substance adsorbed on the NA by measuring its optical absorption under the conditions for which the maximum of the reflectivity response of the 2D-array occurs at the same wavelength of the substance maximum absorption peak. In particular, by acting on the 2D-array periodicity, NA shape, size and thickness, numerical simulations of the 2D-array detection response, based on Finite Element Method (FEM), demonstrate that is possible to obtain an increase in the detection sensitivity of more than three orders of magnitude with respect to that one achievable if the same substance is deposited on an unstructured planar metal surface, independently from the wavelength at which the substance absorption occurs. Moreover, we present the results of an analysis of the dependence of the 2D-array maximum reflectivity and peak wavelength on the geometrical parameters characterising the NA and the 2D-array.