Photon-induced near-field electron microscopy (PINEM) of eukaryotic cells
Photon-induced near-field electron microscopy (PINEM) is a technique to produce and then image evanescent electromagnetic fields on the surfaces of nanostructures. Most previous applications of PINEM have imaged surface plasmon-polariton waves on conducting nanomaterials. Here, the application of PINEM on whole human cancer cells and membrane vesicles isolated from them is reported. We show that photons induce time-, orientation-, and polarization-dependent evanescent fields on the surfaces of A431 cancer cells and isolated membrane vesicles. Furthermore, the addition of a ligand to the major surface receptor on these cells and vesicles (Epidermal Growth Factor Receptor, EGFR) reduces the intensity of these fields in both preparations. In the absence of plasmon waves in biological samples, we propose these evanescent fields reflect the changes of EGFR kinase domain polarization upon ligand binding.
Additional Information© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Manuscript received: June 15, 2017; Accepted manuscript online: July 23, 2017; Version of record online: August 10, 2017. We thank Spencer Baskin and Mohammed Hassan for helpful discussions. This work was supported by the National Science Foundation Grant DMR-0964886 and the Air Force Office of Scientific Research Grant FA9550-11-1-0055 for research conducted in The Gordon and Betty Moore Center for Physical Biology at the California Institute of Technology. The authors declare no conflict of interest.
Accepted Version - 6333722ae81a4c71d4abe7c0cc6ac72953025b6e6d80b258cf357af7b8415fa0.pdf
Supplemental Material - anie201706120-sup-0001-SI1.pdf