This situation is seen particularly clearly with thicker TiO2 lay

This situation is seen particularly clearly with thicker TiO2 layers. To evaluate this spectral shift, one should solve the electromagnetic problem describing the geometry

presented in insets a-c in Figure 9. JQ-EZ-05 nmr However, there still is no any exact solution for this problem, and the reported numerical calculations [27] performed for an isolated hemisphere in a uniform dielectric surrounding (ϵ sub = ϵ cover) have shown that even in this case about 1% rounding of the hemisphere edge results in a meaningful shift of the resonant frequency. In measurements, it is difficult to characterize the curvature of the edges of a nanoisland formed in SOD on a glass substrate, and this does not allow constructing a numerical model for this situation. We can only assume that the shapes of the nanoislands in differently prepared MIFs are very similar. This is indeed indicated by the inset in GSK1210151A supplier Figure 5 as the shift of the SPR under the thickest TiO2 cover is practically the same for all the samples. Figure 9 Schematic of SPR electric field localization (lateral component) in MIF for different dielectric

cover thicknesses. The spectral shift of the SPR saturates when the electric field E generated by a nanoisland under probing electromagnetic wave is completely localized within the covering film and the glass substrate as shown in Figure 9 (inset c). For thinner TiO2 films, the tail of the SPR electric field penetrates through the covering layer, that is,

the electric field is partly localized in the air (see Figure 9, inset b). In other words, the effective dielectric permittivity of the nanoisland surrounding is less for thinner covers than for thicker covers. This results in weaker dielectric loading of the SPR and corresponds to its unsaturated spectral shift, which tends to saturate with the TiO2 film thickness increase. Thus, the saturated SPR shift indicates that the thickness of the cover exceeds the length of the SPR electric field penetration into the cover (Figure 9, inset c). As measured with absorption spectroscopy, the spectral shift of the SPR in TiO2-covered MIF saturates at about 40- to 50-nm cover Ribonucleotide reductase thickness. We can suppose that the SPR electric field intensity decays in TiO2 film at about the same length. Unfortunately, comparing the dependences of the SPR spectral shift in Figure 5, one can hardly conclude whether there is a difference in the SPR decay length for differently prepared MIFs. The measured Raman scattering signal I Raman should decay much faster. If the glass surface is covered with silver nanospheres, [28] for separate molecules and [29] for a monolayer of an analyte, where r is the radius of silver microsphere and d is the distance from the microsphere to the analyte.

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