Describing Single Proteins Located In Membrane Structures by TERS

摘要

Understanding biological processes occurring at the lipid membrane is a hot topic in bioscience since decades. However, the information gained by conventional spectroscopic techniques is averaged since these methods are limited in their spatial resolution. Consequently, nanoscale investigations of single units in membrane structures are virtually impossible. In contrast to conventional microscopy tip-enhanced Raman spectroscopy (TERS), a combination of atomic force microscopy (AFM) and surface-enhanced Raman spectroscopy (SERS), provides a very small scattering volume', thus, enabling a spatial resolution down to 10 nm and below. The technique even allows single molecule detection as investigations of isolated RNA strands have shown3. However, when interested in supported lipid bilayers (SLB) labeled with proteins acting as a membrane model, a clear topographical localization of their functional units is often difficult to achieve, just by AFM information. Furthermore, drawing conclusions about specific states and molecular features with high lateral resolution requires a fast and label free detection scheme, which is provided by TERS.