Fig. 6

Quantification of internalized GNRs (CTAB-GNRs and peptide-f-GNRs) in HeLa and MDA-MB-231 cells by atomic absorption spectroscopy (AAS). The cells were incubated with 0.35 nM GNRs for 2 h. After washing the cells extensively, and lysing by aqua regia, the total gold content in the different wells was measured by AAS. HeLa and MDA-MB-231 cells showed different uptake behavior.*P < 0.05; **P < 0.01; ***P < 0.001