DNA Lipoplex-Based Light-Harvesting Antennae

Abstract

Natural light-harvesting complexes are operated through the well-designed self-assembly of pigments with large protein complexes in a thylakoid lipid bilayer. However, a long-range, directed transfer of excitation energy has not been achieved in artificial systems because the nanoscale arrangement of chromophores into stable micrometer-scale structures is highly challenging. Here the multiscale assembly of chromophores for excited energy transfer through the arrangement of chromophores on nanoscale DNA templates followed by their incorporation into larger multilamellar lipid structures is reported. Single-strand 10 nucleotide DNA molecules containing a terminal residue linked with three different chromophores are hybridized with their complementary 30 nucleotide matrix DNA strand. Due to the short DNA sequences, the energy transfer of the DNA-templated chromophore arrays is limited at 4 degrees C. However, the incorporation of DNA-templated chromophores into lipid-DNA complexes dramatically increases both of the efficiencies and antenna effects of the single and two-step energy transfers at room temperature through the structural stabilization and the secondary assembly of DNA between the interstitial spaces of multilamellar lipid structures. The findings suggest that the supramolecular alignment of DNA-templated chromophores, which has never been explored previously, can be a very promising route toward directed, long-range light harvesting.