Sensitivity enhancement of nanoplasmonic sensors on low refractive index substrates
Journal article, 2009

Metal films perforated by nanoholes constitute a powerful platform for surface plasmon resonance biosensing. We find that the refractive index sensitivity of nanohole arrays increases if their resonance is red-shifted by increasing the separation distance between holes. However, an additional sensitivity enhancement occurs if the nanohole sensors are manufactured on low index substrates, despite the fact such substrates significantly blue-shift the resonance. We find a ∼40% higher bulk refractive index sensitivity for a system of -100 nm holes in 20 nm gold films fabricated on Teflon substrates (n=1.32) compared to the case when conventional glass substrates (n=1.52) are used. A similar improvement is observed for the case when a thin layer of dielectric material is deposited on the samples. These results can be understood by considering the electric field distribution induced by the so-called antisymmetric surface plasmon polariton in the thin gold films.

Author

Björn Brian

Chalmers, Applied Physics, Bionanophotonics

Borja Sepulveda

Chalmers, Applied Physics, Bionanophotonics

Yury Alaverdyan

Chalmers, Applied Physics, Bionanophotonics

LM Lechuga

CSIC-ICN Centro de investigacion en nanociencia y nanotecnologia CIN2

Mikael Käll

Chalmers, Applied Physics, Bionanophotonics

Optics Express

1094-4087 (ISSN)

Vol. 17 3 2015-2023

Subject Categories

Atom and Molecular Physics and Optics

DOI

10.1364/OE.17.002015

More information

Created

10/7/2017