Figure 2: TEM imaging of the MNP-gold-coupled agents.
From: Multifunctional nanoparticles as coupled contrast agents
(a–d) TEM images and (e–h) size distribution histograms of (a) PL-PEG-COOH/PLH-coated MNPs (polymer layer not visible under TEM because of low electron density), and (b–d) MNP-gold core-shell NPs with various shell thickness (b, ~1 to 2 nm; c, 2–3 nm; d, 4–5 nm). Scale bars are 50 nm. (e–h) The particle size histograms are plotted from analysis of >150 particles for each sample. Mean and s.d. for the various distributions are, respectively, 24.4 and 1.3 nm in panel e; 31.7 and 2.5 nm in panel f; 33.9 and 1.9 nm in panel g; and 37.4 and 2.0 nm in panel h. (i–j) Representative high-resolution-TEM images of MNP-gold core-shell NPs with shell thickness of ~2 to 3 nm. The lattice spacing of the MNP core measures at 0.48 nm corresponding to the (111) plane of Fe3O4, whereas the (111) plane of face-centred cubic (fcc) Au shows 0.23 nm lattice spacing. The scale bar is 5 nm for panel i and 2 nm for panel j.
