Nanoscale structural analysis using tip-enhanced Raman spectroscopy.

Tip-enhanced Raman scattering (TERS) enables the label-free investigation of biochemical interfaces with nanometer lateral resolution by combining the benefits of the intrinsic molecular specificity of Raman spectroscopy, the sensitivity because of signal enhancing capabilities of plasmonic nanoparticles, and the precision of scanning probe microscopy. The structural differentiation of constituents based on inherent molecular information is possible even down to a few nanometer spatial resolution and consequently, nucleobases, proteins, lipids, and carbohydrates can be identified and localized in a single measurement. This has been shown in the last few years for different biological samples ranging from single DNA strand investigations to cell membrane studies.