720579.fig.003
Figure 3: UV-vis spectra of (a) PS1 and PS-GNPs conjugates 2a2e with various molar ratios between gold and Pu-18-NMGA in water (2a, Au:Pu-18-NMGA = 1 : 2; 2b, 1 : 4; 2c, 1 : 6; 2d, 1 : 8; 2e, 1 : 10).