Fig. 1

Colloidal stability of Au-3-PEG (a–c) and Au-4-COONa (d–f) NPs in EM. a, d Au-3-PEG and Au-4-COONa NP suspensions in EM (19.2 μg/mL Au each) after 0, 6 and 24 h of static incubation (37 °C/5% CO₂) in the absence of cells. b, e Scattering intensity as function of scattering vector q and c, f pair distance distribution function (PDDF) of the PEGylated and carboxylated AuNPs in EM. g Diameter of gyration (d_gyr; mean ± error) calculated from SAXS data and hydrodynamic diameter from DLS analysis (d_hyd; Z-Average)