Scattering phenomena electromagnetic waves

Fig. 5.1. Phenomenon of interference of electromagnetic waves such as hght and X-rays illustrated by a simple case of two scattering atoms.

The fascinating phenomenon of surface plasmon resonance (SPR) occurs when an electromagnetic wave interacts with the conduction electrons of a metal (6). The periodic electric field of the electromagnetic wave causes a collective oscillation of the conductance electrons at a resonant frequency relative to the lattice of positive ions. Light is absorbed or scattered at this resonant frequency. The process of... [Pg.541]

Alternatively, various analytical methods based on SPR phenomenon have been developed, including surface plasmon field-enhanced Raman scattering (SERS) [7], surface plasmon field-enhanced fluorescence spectroscopy (SPFS) [8-11], surface enhanced second harmonic generation (SHG) [12], surface enhanced infrared absorption (SEIRA) [13], surface plasmon field-enhanced diffraction spectroscopy (SPDS) [14-18], Most of these methods take advantage of the greatly enhanced electromagnetic field of surface plasmon waves, in order to excite a chromophoric molecule, e.g., a Raman molecule or a fluorescent dye. Therefore, a better sensitivity is expected. [Pg.56]