Figure 2.

Synthesis of AuNPs at physiological temperature and their tonality characterizations. a) Demonstration of generated AuNPs with different colors dependent on the concentrations of 100 µL of HAuCl₄ from 0.25 × 10⁻³ to 2.5 × 10⁻³ m in 100 µL of 2 × 10⁻³ m of trisodium citrate solution at 37 °C. The absorbance values of the solution at 550 nm are plotted against varying concentrations of HAuCl₄. b) UV–vis spectra of AuNPs generated with HAuCl₄ concentrations of 1 × 10⁻³ m (green line) and 0.5 × 10⁻³ m (black line), respectively. Inset: Photographs of the corresponding AuNPs solutions.