Double functionalization of carbon nanotubes with purine and pyrimidine derivatives

Herein, we have developed a synthetic strategy for the covalent double functionalization of single-walled carbon nanotubes (SWCNTs) with a combination of purine-pyrimidine and purine-purine nucleobase systems. The nucleobases were introduced on the sidewall of oxidized SWCNTs through 1,3-dipolar cycloaddition and by amidation of the carboxylic acids located at the tips and defect sites of the nanotubes. The new nanohybrids were characterized by transmission electron microscopy, thermogravimetric analysis, FTIR and Raman spectroscopy, magic-angle spinning NMR spectroscopy, and Kaiser test. The nucleobase/SWCNT conjugates can be envisaged for the modulation of the interactions with nucleic acids by means of base pairing, thereby opening new possibilities in the development of DNA/CNT nanobioconjugates.