Figure 2.

TEM images of DFNS/Au nanohybrids synthesized by using various HAuCl₄(aq) concentrations (scale bar: 100 nm): a) 1.25 mm, b) 2.5 mm, c) 5 mm, d) 10 mm, e) 20 mm, and f) 30 mm HAuCl₄(aq) (the same volume of the second growth solution, 0.8 mL, is used in all cases). Based on the synthesis ratio (molar ratio=amount of HAuCl₄ in the growth solution/ amount of HAuCl₄ in the DFNS/Au dots), the reaction ratios can be assigned as: a) 7, b) 15, c) 30, d) 61, e) 123, and f) 246.