抄録
Metallic nanostructures exhibit optical resonance, where free electrons oscillate at the surface, creating
strong near field. This resonance wavelength is sensitive to the surrounding refractive index, and
therefore a subtle change of the surrounding environment can be monitored by tracking the resonance.
This sensing scheme can be applied to detect biological targets by properly functionalizing the surface.
In this article we describe how such nano-biosensors work as well as application examples using
plasmonic nanostructures. Since the optical fi eld distribution at the metal surface determines the sensor
performance, we also show how nanoscopic optical fi eld can be experimentally visualized by electron
microscopy based methods.
