Mussel-Inspired Surface Coating to Stabilize and Functionalize Supramolecular J-Aggregate Nanotubes Composed of Amphiphilic Cyanine Dyes

We report a mussel-inspired strategy of polydopamine coating to stabilize and functionalize J-aggregate nanotubes formed by supramolecular self-assembly of an amphiphilic cyanine dye called C8S3 in aqueous media. Optimization of the coating condition by changing the incubation time in a slightly basic media of dopamine with different concentrations leads to conformal wrapping of the polydopamine layer with controllable thickness on the surface of the nanotubes. Compared to noncoated pristine C8S3 nanotubes, these polydopamine-coated nanotubes show enhanced stability against dilution, heating and photobleaching. Moreover, the polydopamine layer wrapping around the nanotubes serve as an adhesive for adsorption of a variety of metal ions and electroless deposition of the metal nanoparticles. Such stabilized and functionalized nanotube composites may offer a robust synthetic J-aggregate system to mimic the structure and function of light-harvesting complexes and reaction centers in photosynthetic systems.