Figure 3.

(a) Reaction sequences of in situ reaction of naringin with 0.25 mM of aqueous HAuCl₄, at pH = 2.5, 7, and 11.5. Bottles “E”, “B”, and “F” show the Au NP solutions prepared, respectively. Au NPs of bottle “E” and “B” can be made stable suspensions with basic medium and glycerol, respectively, while that of “F” can be extracted into the organic phase. (b,c) UV–visible scans of the respective samples. TEM images of Au NPs (d) prepared with naringin and (e–g) prepared with its chalcone. Inset of (g) depicts the XRD patterns of Au NPs. See details in text.