Site-Specific Immobilization of Single-Walled Carbon Nanotubes onto Single and One-Dimensional DNA Origami

Development of a simple and efficient methodology to control the placement, spacing, and alignment of single-walled carbon nanotubes (SWCNTs) is essential for nanotechnology device application. Building on the growing understanding that the strong pi-pi interaction between the bases of single-stranded DNA (ssDNA) and CNTs is sufficient not only to drive CNT solubility in water but also to stabilize individual nanotubes against clustering in aqueous solution, a new motif for functionalizing DNA origami (DO) with CNTs is demonstrated. CNTs solubilized via wrapping with ssDNA react with DO constructs displaying linear arrays of ssDNA, leading to immobilization of the CNTs onto the DO scaffold. This study demonstrates the immobilization of ssDNA-wrapped CNTs at specific positions on single DO constructs. Furthermore, multiple DO constructs assembled into extended one-dimensional arrays have been used to successfully align pairs of CNTs exceeding 500 nm in length in a parallel orientation. This result provides a simplified, alternative approach to immobilization of CNTs with programmed spacing and orientation.