Probing Membrane Receptors with Enhanced Raman Imaging.

Our lab has shown that nanoparticles functionalized with short peptides can selectively bind to receptor proteins in vitro. Our results indicate that the Raman signals observed from purified receptors in surface enhanced Raman scattering (SERS) experiments match those observed with tip-enhanced Raman scattering (TERS) experiments performed on membrane receptors in intact cell membranes. Analysis of the observed Raman signals suggest the signals arise from the amino-acids in the protein receptor responsible for binding and recognition of the ligand attached to the nanoparticle probe. Further experiments show the variance in the data correlates with affinity of the nanoparticle probe with a specific receptor. This result illustrates a new approach to studying membrane receptors.