Figure 1.

Loading efficiency and loading capacity of doxorubicin (DOX) on graphene oxide (GO) sheets as a function of the GO/DOX weight ratio R_W. (a) GO-DOX complexes were centrifuged, and the pellet was washed three times with ultrapure water (indicated as S1, S2 and S3 respectively). (b) Absorbance spectra measured from the supernatants. After the third washing step, the pellet was resuspended in ultrapure water and the solution (P) used for (c) quantification of DOX loading efficiency (black squares) and capacity (grey triangles).