
116 Biosensors Based on Nanomaterials and Nanodevices
6.2.2 Technical Rationale and Approach of SERS
As discussed in the previous section, the Raman scattering intensity is proportional to the
excitation eld intensity. To obtain higher Raman scattering signals, apparently, one can
think of using extremely high-power light sources such as kilowatt or megawatt lasers to
excite the target molecules; however, this approach is not practical because such a power-
ful light source is not commonly available and the corresponding optics are expensive.
Alternatively, one can think of articially creating a hotspot by concentrating the excita-
tion energ ...