Spheres, metals distribution between

In this section we present worked examples demonstrating application of the theory described earlier. In the first example we demonstrate a familiar simple electrostatic problem in which a metal sphere is held at a potential of 1V and is enclosed in a cubical grounded metal box (Fig. 15.5). The task at hand is to find the potential distribution in volume E between the sphere and the box. 

An increase in excitation of the fluorophore depends on the spectral overlap between the SPR and the excitation spectrum of the molecule and on the enhancement of the local field which, as can be seen below, depends on the position of the fluorophore and its distance from the metal surface. The distribution of the local (enhanced) fields for a nanoprism and nanorod are illustrated in Figure 11.11 [S]. The largest field intensities occur at the tips of the nanoprism and at the ends of the nanorods. The field intensities are calculated to be approximately 4000 times the applied field. These field enhancements are much larger than can be obtained with spheres. Even larger field oihancements can be obtained at the interface of nanoparticles in very close proximity to one another, as shown in Figure 11.12 [5]. 

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