Figure 6

Wrapping of ssDNA around single-walled carbon nanotubes (CNTs). DNA wrapping can be seen in AFM topography (A) and even better in AFM phase contrast images (B). (C) Exposure to end-thiolated DNA results in densely DNA wrapped CNTs that carry regularly spaced functional groups on their surface allowing attachment of mercaptoacetic acid capped QDs (white features on the CNT, nominal QD diameter 2.4 nm) via disulphide bonds . In the section view, (1) denotes a position on the mica substrate while (2) indicates a quantum dot coupled to the CNT. The height scale of (A) and (C) is 5 nm. Reprinted with permission from [83], coyright 2008 American Chemical Society.