Energy Transfer in Nanotube-Perylene Complexes

A functional surfactant designed to solubilize and individualize nanotubes efficiently in aqueous media and to form energy transfer complexes with the carbon nanotubes through π–π stacking is presented. Upon excitation of the adsorbed perylene unit an emission from the nanotubes is observed that indicates a successful excitation transfer. The efficiency of the indirect excitation via the adsorbant is of the same order of magnitude as the direct excitation of the nanotubes. Under optimized preparation conditions the pH independent perylene-imido-diester compound isolates and solubilizes carbon nanotubes in biocompatible aqueous environments without additional surfactants. The resulting solutions are stable over many months.