Surface-enhanced Raman spectroscopy wavelength dependence

From Eq. (33.6), it is clear that the SPR wavelength position depends on the optical characteristics of the surrounding media and consequently if the environment changes or has fluctuations, the plasmon resonance will shift its location. The Frolich condition is directly associated with an electromagnetic field enhancement that takes place in the vicinity of metallic NP due to the collective excitations of the electrons. These concepts are the first stones in the use of plasmonic devices as sensors, as it is the case of svuface-enhanced Raman spectroscopy. Ordered OMPO structures filled with silver NPs are suitable substrates for SERS as they give a reproducible enhancement over a wide surface area (Figure 33.8b and c). 

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