Document Type

Article

Publication Date

2010

Publication Title

Journal of Applied Physics

Volume

107

Issue

9

First Page

094303-1

Last Page

094303-6

Abstract

We propose a sensing mechanism for detection of analytes that can specifically recognized. The sensor is based on closely-spaced chains of functionalized gold nanoparticles (NPs) immobilized on a waveguide surface, with the signal detected by evanescent waveguide absorption spectroscopy. The localized surface plasmon spectrum of a linear array of closely-spaced, hemispherical gold NPs is calculated using the discrete dipole approximation. The plasmon band is found to broaden to a nanowirelike spectrum when a dielectric coating is put on the particles, and the light polarization is along the NP chain. The origin of this broadening is shown to be the polarization-dependent overlap of the evanescent fields of adjacent NPs upon application of the dielectric coating. These features suggests a mechanism for biosensing with an improved sensitivity compared with traditional NP biosensor methods.

Comments

This article was first published in the Journal of Applied Physics, Vol. 107 Iss. 9, 2010. Copyright (2012) American Physical Society (APS). It can be found here.

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