Figure 3

TEM images of uncoated and PEG-coated AuNPs. TEM images of uncoated AuNPs: (A) 16-nm AuNPs and (H) 26-nm AuNPs. TEM images of fully coated AuNPs in the absence of 10.0% (w/v) NaCl solution for 16-nm AuNPs: (B) APEG 600, (C) APEG 6,000, and (D) APEG 20,000; for 26-nm AuNPs: (I) APEG 600, (J) APEG 6,000, and (K) APEG 20,000. TEM images of fully coated AuNPs in the presence of 10.0% (w/v) NaCl solution for 16-nm AuNPs: (E) APEG 600, (F) APEG 6,000, and (G) APEG 20,000; and for 26-nm AuNPs: (L) APEG 600, (M) APEG 6,000, and (N) APEG 20,000. The t represents the thickness of the dehydrated PEG adlayer (red line). The scale bars are 5 nm (A to D), (H to K) and 100 nm (E to G), (L to N), respectively.