Thymidine-functionalized silica nanotubes for selective recognition and separation of oligoadenosines

Thymidine receptor residues were covalently attached to the inner side wall of silica nanotubes (SNTs). The adsorption capacities of the thymidine-functionalized silica nanotubes (T-SNTs) with nucleic acids and oligonucleic acids were evaluated. The T-SNTs exhibited excellent selectivity both in recognition and separation of adenosine and adenosine-based oligonucleotides, because adenosine and oligoadenosine were selectively bound to the inner surface of T-SNTs by formation of complementary intermolecular hydrogen bonds. On the other hand, guanosine, cytosine and oligoguanosine derivatives were not bound to the T-SNTs. The T-SNTs selectively separated 95% of oligoadenosine from a mixture of equal amounts of oligocytosine and oligoguanosine. Our results imply that the T-SNTs can be used as a selective receptor and separator for the extraction and separation of adenosine and oligoadenosine derivatives in aqueous solution.