Fig. 1. (a) XANES spectra of the Ag L2,3 edge in the region of the sea
urchin embryo indicated by the black circle in (b), using a beam spot
size of 0.2 µm x 0.8 µm, with the pixel size 0.5 µm x 0.5 µm. (b) the
XRF map in reversed grayscale of a sea urchin exposed to AgNPs at
concentration of 0.3 mg/L after 51 h of growth. The size of sea
urchin larva image is 100 µm x 100 µm. The encircled black spot
(around 2-5 µm) indicates the presence of agglomerated AgNPs in
sea urchin.
In fig. 2 the XANES spectrum from agglomerated AgNPs
in the sea urchins (bottom) is compared with reference
spectra from AgCl, Ag foil, AgNO3, Ag2O, AgO and Ag2S (Yin et
al., 2011). The data show that the edge of the spectrum from
AgNPs in the sea urchins is clearly associated with Ag, but