Figure 4.

Phase and magnitude ptychographic images of cellular structure with functionalized nanoparticles. (a) Phase image of the ptychographic reconstruction of the leading edge of a HeLa cell labeled with core-shell nanoparticles showing high contrast for cellular features such as membrane ruffles and fillipodia. (b) Magnified views of the regions outlined by dashed boxes in (a), including (left to right) nanoparticles alone, graphene-oxide coated lacey carbon, cell and nanoparticles, and cell alone. The magnified view of the nanoparticles also demonstrates the phase’s ability to discern the silica shell (light gray halo around cores indicated by black arrows) as well as the two different oxidation states (light and dark cores). A larger version of this can be seen in Supplementary Fig. 13. (c) Magnitude image of the ptychographic reconstruction showing high contrast for the Fe₃O₄ cores of the nanoparticles. (d) Magnified views of the same regions shown in (b), highlighting the different features that can be sharply resolved between the phase and magnitude images. Scale bars represent 500 nm (a and c) and 200 nm (b and d).