631350.fig.008a
(a)
631350.fig.008b
(b)
Figure 8: TEM images of CTAB-covered AuNRs after reaction with (a) citrate-stabilized AuNSs and (b) CTAB-stabilized AuNSs. The bare ends of AuNRs adsorb the citrate-stabilized AuNSs, whereas CTAB-stabilized AuNSs only accumulate near the sides of AuNRs. CTAB tends to be adsorbed by the sides of AuNRs in solutions containing a low concentration of CTAB. Scale bars are 100 nm. Reproduced with permission from [32]. Copyright 2008 American Chemical Society.