Tip-enhanced Raman spectroscopy: near-fields acting on a few molecules.

Tip-enhanced Raman spectroscopy (TERS) is a very powerful variant of surface-enhanced Raman spectroscopy (SERS). In a sense, TERS overcomes most of the drawbacks of SERS but keeps its advantages, such as its high sensitivity. TERS offers the additional advantages of high spatial resolution, much beyond the Abbe limit, and the possibility to correlate TER and other scanning probe microscope images, i.