Morphological effects, surface plasmon

Kujawa, P., Moraille, P., Sanchez, J., Badia, A., Winnik, F. Effect of molecular weight on the exponential growth and morphology of hyaluronan/chitosan multilayers a surface plasmon resonance spectroscopy and atomic frace mitaoscopy investigation. J. Am. Chem. Soc. 127, 9224-9234 (2005)... 

This effect is known as surface enhanced Raman scattering (SERS) [10-12]. The SERS effect has been widely investigated for various molecules adsorbed on rough metallic surfaces or on metallic clusters in colloids. Reviews on this topic can be found in Refs. [12-15]. The enhancement of normally Raman-active modes is a consequence of the enhancement of the electric field of the incoming and scattered radiation in the vicinity of a rough metal film upon coupling with the dipolar plasmon resonances in the metal clusters. This enhancement affects molecules located up to even 10 nm away from the metal surface [11, 12]. The enhancement factors are essentially determined by the electronic properties of the metal and by the morphology of the metal film. 

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