Experimental parameters used in the DoE phase.
| Symbol | Predictors and responses | Level | Unit |
|---|---|---|---|
| X 1 | Synthesis temperature | 100 (1), 120 (2), 150 (3), 180 (4) | °C |
| X 2 | Synthesis time | 1 (1), 5 (2), 30 (3), 180 (4) | Min |
| X 3 | Precursor concentration | 0.083 (1), 0.25 (2), 0.75 (3), 2.5 (4) | mM |
| X 4 | Heating rate | As fast as possible (AFAP; 1), 20 (2), 5 (3) | °C min−1 |
| X 5 | Metal precursor | HAuCl4 (1), AgNO3 (2), Na2PdCl4 (3) | — |
| X 6 | Hydrogel choice | Alginate (1), agarose (2) | — |
| Y 1 | Diameter | — | nm |
| Y 2 | Circularity | — | — |
| Y 3 | Polydispersity | — | — |