3.1.3. Synthesis of Au@16-Ph-16 Gold Nanoparticles

To prepare 16-Ph-16 functionalized gold nanoparticles, 300 μL of aqueous solution of 23 mM HAuCl₄ at 99.9% purity was added to 30 mL of 16-Ph-16 surfactant 4 × 10⁻⁵ M and the mixture was stirred vigorously for 5 min in the absence of light, giving a yellow solution. Subsequently, 100 μL of a freshly prepared 0.4 M NaBH₄, 96% pure, aqueous solution was added dropwise to the previously prepared mixture and stirred moderately for 15 min in the darkness, acquiring a reddish color [40]. As a result, an aqueous solution of Au@16-Ph-16 nanoparticles at 5.6 × 10⁻⁸ M concentration was obtained. In this work, we employed three formulations (N_I) of Au@16-Ph-16 prepared at different C_16-Ph-16 concentrations of 3.4, 6.7 and 9.4 nM, which were designated as N₁, N₂ and N₃, respectively. The concentrations of Ns, Cs and Cs + Ns were the same in each system tested.