Synthesis of nucleobase-functionalized carbon nanotubes and their hybridization with single-stranded DNA

For the first time ssDNA (25-aptamer of mixed dA, dT, dG, and dC) was wrapped around functionalized single-walled carbon nanotubes (SWCNTs), whose external surfaces were attached to multiple triazole-(ethylene glycol)-dA ligands. This method of hybridization involved the formation of hydrogen bonds between dT of ssDNA and dA of functionalized SWCNTs. It deviates from the reported π-π stacking between the nucleobases of DNA and the external sidewalls of nanotubes. The structural properties of the functionalized SWCNTs and its ssDNA complex were characterized by spectroscopic (including CD and Raman), thermogravimetric, and microscopic (TEM) methods. The results thus obtained establish a new platform of DNA delivery by use of nanotubes as a new vehicle with great potential in biomedical applications and drug development.