A simple model for the resonance shift of localized plasmons due to dielectric particle adhesion

• Ultrasensitive detectors based on localized surface plasmonresonance refractive index sensing are capable of detecting very lownumbers of molecules for biochemical analysis. It is well known that thesensitivity of such sensors crucially depend on the spatial distribution ofthe electromagnetic field around the metal surface. However, the preciseconnection between local field enhancement and resonance shift is seldomdiscussed. Using the quasistatic approximation, we developed a model thatrelates the sensitivity of a nanoplasmonic resonator to the local field inwhich the analyte is placed. The model, corroborated by finite-differencetime-domain simulations, may be used to estimate the magnitude of theshift as a function of the properties of the sensed object – permittivity andvolume – and its location on the surface of the resonator. It requires onlya computation of the resonant field induced by the metal structure and istherefore suitable for numerical optimization of nanoplasmonic sensors.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Telekommunikation (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Telecommunications (hsv//eng)

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)