Fig. 1. UV-Vis absorption spectra of GNPs synthesized with different extract dilutions for HAuCl4 concentration of 1 × 10−2 M (panel A) and 1 × 10−3 M (panel B), collected on day 1 (dashed lines) and day 5 (continuous lines). The maximum optical extinction and the plasmon band location as function of extract dilution are shown in panels (C) and (D) respectively.
