Fig. 5. SEM micrograph (a) of SiO2-Lys-SP-NCs. Scale bar of 1 μm. In the inset, TEM micrograph of a single-NC with a scale bar of 100 nm. Dry size distribution and Gaussian fit comparison (b) between uncoated (top, R2 = 98%) and coated (bottom, R2 = 88%) SP-NCs, highlighting the (double) shell thickness (170 nm). EDX mapping (c) of a single SiO2-Lys-SP-NC, detecting Fe Lα and Si Kα characteristic X-ray emission lines. Scale bar indicates 250 nm.
