Table 1.
Physico-chemical properties of QDs used in the study
| Sample | Hydrodynamic diameter [nm] | Height (TEM) [nm] | Zeta potential [mV] | ||||
|---|---|---|---|---|---|---|---|
| Water | DPBS | MEM+ | Water | DPBS | MEM+ | ||
| QD-COOH | 17 ± 4 (21 %) | 19 ± 4 (22 %) | 10 ± 4 (37 %)a | 13 ± 1 | −39 ± 3 | −36 ± 2 | −8 ± 3 |
| QD-NH2 | ND | ND | 34 ± 18 (53 %) | 13 ± 1 | −36 ± 1 | −2 ± 0 | −3 ± 1 |
| QD-PEG | ND | 38 ± 10 (25 %) | 11 ± 4 (41 %)a | 14 ± 1 | −25 ± 0 | 0 ± 2 | −3 ± 1 |
a Pure cell culture medium (MEM+) without QDs was measured as a reference and hydrodynamic diameters of 7 ± 2 nm were obtained representing the size of BSA, which is the most abundant protein in MEM+.The measured values therefore rather represent the hydrodynamic diameter of the proteins in the medium