2.2. Synthesis of Gold Nanoparticles Using the Citrate Method

Citrate-capped gold nanoparticles were synthesized via the Frens method [16] with modifications according to our paper [48]. An aqueous solution of HAuCl₄ was added to deionized water, as indicated in Table 1, and the mixture was brought to a boil. Then, a solution of sodium citrate (see Table 1) was added with stirring. The mixtures were boiled for 25 min, and then cooled and stored at 4–6 °C. The obtained colloids were labeled C-GNPs-1–C-GNPs-5.

Proportions of reagents for gold nanoparticles preparation using the Frens method.