Fig. 2

TEM images and UV-vis absorption spectrum of gold nanoparticles. a TEM images of ~ 10-nm citrate-coated gold nanoparticles; b Low magnification TEM images of Au-siRNA-PAA-AS1411 nanocages; c TEM images of Au-siRNA-PAA-AS1411 nanocages with negative staining; d Changes in the UV-Vis absorption spectrum of citrate-coated gold nanoparticles, Au-ssDNA and Au-dsDNA; The UV-Vis of the Au-dsDNA and Au-ssDNA (DNA-2 : siRNA = 1:10 molar ratio) exhibited a 5 nm and 3 nm wavelength shift, respectively, compared with the Au nanoparticles, showing the successful modification of DNAs on the surface of gold nanoparticles. e The gel image of Au, Au-siRNA, and siRNA showing the successful coating of siRNAs. The band of siRNA located at a molecular weight lower than that of Au-siRNA indicates that siRNAs were successfully conjugated on the surface of Au nanoparticles