A method for joining nanotubes end-to-end, includes contacting the nanotubes with a joining fluid. The joining fluid has at least one property that is different from at least one property associated with ends of the nanotubes. In one embodiment, the method further includes contacting the nanotubes with a first, treating fluid and removing the bulk first fluid before the nanotubes are contacted with the joining fluid. The joining fluid is immiscible in the treating fluid to effect end-to-end joining of the nanotubes.