Confocal Fluorescence Imaging of DNA-Functionalized Carbon Nanotubes

Single-walled carbon nanotubes (SWNT) were covalently modified with DNA via carbodiimide-assisted amidation, yielding a highly water-soluble 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.