Confocal fluorescence imaging of DNA-functionalized carbon nanotubes

Single-walled carbon nanotubes (SWNT) were covalently modified with DNA via carbodlimide-assisted amidation, yielding a highly watersoluble adduct. The specific and nonspecific interactions between DNA and SWNTs were examined by UV-vis spectroscopy and confocal fluorescence microscopy. Fluorescence imaging of individual bundles shows that the SWNT-DNA adducts hybridize selectively with complementary strands with minimal nonspecific interactions with noncomplementary sequences.