A simple model for the resonance shift of localized plasmons due to dielectric particle adhesion
Journal article, 2012

Ultrasensitive detectors based on localized surface plasmon resonance refractive index sensing are capable of detecting very low numbers of molecules for biochemical analysis. It is well known that the sensitivity of such sensors crucially depend on the spatial distribution of the electromagnetic field around the metal surface. However, the precise connection between local field enhancement and resonance shift is seldom discussed. Using the quasistatic approximation, we developed a model that relates the sensitivity of a nanoplasmonic resonator to the local field in which the analyte is placed. The model, corroborated by finite-difference time-domain simulations, may be used to estimate the magnitude of the shift as a function of the properties of the sensed object – permittivity and volume – and its location on the surface of the resonator. It requires only a computation of the resonant field induced by the metal structure and is therefore suitable for numerical optimization of nanoplasmonic sensors.

Author

Tomasz Antosiewicz

Chalmers, Applied Physics, Condensed Matter Theory

Peter Apell

Chalmers, Applied Physics, Condensed Matter Theory

Mikael Käll

Chalmers, Applied Physics, Bionanophotonics

Virginia Claudio

Chalmers, Applied Physics, Biological Physics

Optics Express

1094-4087 (ISSN)

Vol. 20 1 524-533

Areas of Advance

Nanoscience and Nanotechnology

Life Science Engineering

Materials Science

Subject Categories

Telecommunications

DOI

10.1364/OE.20.000524