581Future Trends of Nanosensors
surface of metallic NPs and function by transducing small changes in the
refractive index near the metallic surface into a measurable wavelength shift
response (Barbillon et al. 2007). What are the prospects of SERS-based nanosens-
ing? Compared with the refractive index–based detection schemes, SERS is a
vibrational spectroscopic method that yields unique vibrational signatures
for small molecule analytes, as well as quantitative information (Kneipp et
al. 2010). The SERS signal transduction mechanism has many characteristics
that can be utilized in biosensing applications: sensitivity, selectivity, low
laser power, and no interference from water molecules. Examples are trace
analysis of DNA, bacteria, glucose ...