Tip Enhanced Raman - Force Spectroscopy characterization of single protein molecules on cell membrane surface

Investigation of single protein molecules on cell membrane surface


​The behavior of cell membrane proteins in their physiological environment is very well characterized in terms of optical microscopy but at the poor resolution level of several hundreds of nanometers. This disadvantage is unavoidable due to the physical properties of light. We could overcome this limitation thanks to a new technique by which we perform force spectroscopy curves over a cell membrane surface with a TERS nanofabricated probe able to generate the excitation of specific molecules responding with Raman shift data related to the single molecule mechanical unfolding. The result is a chemical –mechanical map of the single protein present on the cell surface. This approach is important because it could elucidate some mechanisms of diseases related to conformational changes of the protein, but at the single molecule level with nanometric resolution. Energy landscapes determination, relation to the cell membrane environment, chemical fingerprint of different mutants, possibility to change environment conditions to simulate a disease or to stimulate a cell response, these are the scenarios where the Tip Enhanced Raman-Force Spectroscopy is applied.