Localized surface plasmon resonance 612 INDEX

Keywords Nanostructures Surface plasmon resonance Localized surface plasmon resonance Bio-molecular interactions Refractive index change Effective medium Thin films Biosensors Sensitivity Nanoparticles... 

Thus the value of the dielectric constant at the sample/metal interface determines the shift of the resonance. When adsorption of molecules at the metal surface results in the change of the refractive index or of the local value of the dielectric constant, the change of reflectivity is observed. This phenomenon has been used as the mechanism for detection of gases (Fig. 9.18a) and of adsorbed biomolecules (Fig. 9.18b). The depth of penetration of the surface plasmon is comparable to that of the evanescent field, that is, 100-500 nm for the visible-near infrared range. 

Interaction of biomolecules with the surface of metallic nanoparticles may also result in local changes in refraction index. This in turn may result in delicate modification of plasmon resonance frequency and yield detectable analytical signal [138],... 

Local variations in index of refraction upon a binding event trigger a change in resonance of surface plasmons, tracked dynamically... 

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