289371.fig.0011a
(a)
289371.fig.0011b
(b)
Figure 11: (a) Zoom in on the main MB peak at 1623 cm−1 of methylene blue adsorbed on a 15 nm diameter NPs multilayer structure and Au thermal evaporated film obtained by SERS. (i) (blue curve) Au evaporated thermally evaporated film, (ii) (red curve) three layers of nanoparticles hybrid architecture, (iii) (green curve) five layers of gold nanoparticles hybrid architecture. (b) Evolution of the intensity of the main MB peak at 1623 cm−1 of methylene blue adsorbed NPs multilayer structure versus the number of layers.