Influence of the Evanescent Field Decay Length on the Sensitivity of Plasmonic Nanodisks and Nanoholes
Journal article, 2015

We evaluate and compare the sensitivity of gold nanodisks on silica substrates and nanoholes made in silica-supported gold films, two of the most common sensor structures used in plasmonic biosensing. An alumina overcoat was applied by atomic layer deposition (ALD) to precisely control the interfacial refractive index and determine the evanescent plasmonic field decay length. The results are in good agreement with analytical models and biomolecular binding experiments for the two substrates. We found that nanodisks outperform nanoholes for thin dielectric coatings ( similar to 20 nm). The optimum nanoplasmonic transducer element for a given biorecognition reaction can be chosen based on experimentally determined bulk sensitivities/noise levels and theoretically estimated evanescent field decay lengths.

atomic layer deposition

nanodisk

surface plasmon resonance

biosensing

nanohole

plasmonics

Author

Francesco Mazzotta

Chalmers, Applied Physics, Biological Physics

T. W. Johnson

University of Minnesota System

Andreas Dahlin

Chalmers, Applied Physics, Bionanophotonics

J. Shaver

University of Minnesota System

S. H. Oh

University of Minnesota System

Fredrik Höök

Chalmers, Applied Physics, Biological Physics

ACS Photonics

2330-4022 (eISSN)

Vol. 2 2 256-262

Subject Categories

Atom and Molecular Physics and Optics

Nano Technology

DOI

10.1021/ph500360d

More information

Created

10/7/2017