Table 1.
Au NP characterization
| Au NP nominal size | STEM
|
DLS in native solution
|
CPS in native solution
|
CPS in MEM
|
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean ± SD (nm) | Mean ± SD (nm) | PDI | Z-pot (mV) | Mean (nm) | Half-width (nm) | PDI | Mean (nm) | Half-width (nm) | PDI | |
| 5 nm | 3.3±1.7 | 7.1±2.1 | 0.097 | −26±11 | 6.6 | 2.2 | 1.37 | 3.4 | 1.5 | 5 |
| 15 nm | 12.0±1.0 | 17.0±4.7 | 0.028 | −30±12 | 12.9 | 1.7 | 1.04 | 7.4 | 1.3 | 2.3 |
Notes: Mean size distribution ± SD of 5 nm and 15 nm Au NPs measured in native solution by STEM, DLS, and CPS. PDI and Z-potential values are also included. Values are expressed as mean of three measurements for DLS and CPS, and for STEM analysis of at least 300 NPs. The mean size distribution of 5 nm and 15 nm Au NPs obtained by CPS was measured in MEM after 72 hours of incubation at 37°C. Z-potential measurements of the as-synthesized Au NPs were performed at the physiological pH range of 6.5–7.5.
Abbreviations: Au NP, gold nanoparticle; CPS, centrifugal particle sedimentation; DLS, dynamic light scattering; MEM, minimal essential medium; PDI, polydispersity index; SD, standard deviation; STEM, scanning transmission electron microscopy; Z-pot, Z-potential.