Spatially controllable DNA condensation by a water-soluble supramolecular hybrid of single-walled carbon nanotubes and beta-cyclodextrin-tethered ruthenium complexes.

A supramolecular hybrid is prepared by the supramolecular surface modification of single-walled carbon nanotube (SWCNT) with cationic beta-cyclodextrin-tethered ruthenium complexes through a spacer molecule that contains both an adamantane and a pyrene moiety. By employing the supramolecular hybrid, spatially controllable DNA condensation along the SWCNT skeleton is achieved by anchoring cationic ruthenium complexes on the surface. Furthermore, because of the unique physiological properties of SWCNTs, the cationic supramolecular hybrid can be used as a nonviral gene delivery system with the ruthenium complexes as a fluorescent probe to monitor uptake of DNA by cells.