Evidence and use of metal-chromophore interactions: luminescence dichroism of terthiophene-coated gold nanoparticles in polyethylene oriented films

Nanocomposites with unusual and anisotropic optical properties have been obtained through the dispersion of gold nanoparticles and gold-binding chromophores in a stretched polymer matrix (Ultra High Molecular Weight PolyEthylene, UHMWPE). Strongly dichroic terthiophene-based chromophores, previously used in anisotropic UHMWPE dispersions, were modified with a thiol group and used for the preparation of gold nanoparticles. We demonstrate that the electronic systems of the chromophores are coupled with the gold nanoparticles. For the first time, evidence is reported that the polarization of the absorbed radiation can be preserved during energy transfer between a chromophore and a metal particle.