Self-Assembled Supramolecular Films Derived from Marine Deoxyribonucleic Acid (DNA)−Cationic Surfactant Complexes:  Large-Scale Preparation and Optical and Thermal Properties

Series of polyelectrolyte−surfactant complexes, DNA−cationic surfactant complexes (cetyltrimethylammonium, cetylpyridinium, and cetylbenzyldimethylammonium), and their self-assembled bulk film materials were prepared on a large scale. Circular dichroism (CD) analysis indicated that the right-handed double helix structure of DNA was retained in these bulk film materials. TGA analysis suggested that 4 molecules of water were required to retain the B-type conformation of the DNA helix in the self-assembled bulk film materials. In addition, it revealed that DNA and the DNA−surfactant complex film materials were thermostable up to as high as 180 °C. Thermodynamical analysis indicated that these film materials were thermo-extensive over a temperature range from 100 to 148 °C. The DNA conformation in the supramolecular complex films can be reversibly tuned by changing the environmental humidity. Film formation was found to occur by self-assembly and self-organization with evaporation of solvent molecules. Various functional dyes such as laser dye, NLO dye, and photochromic dye could easily be incorporated in the self-assembled supramolecular complex films as adducts. Studies of the induced CD spectra demonstrated that 44-(dimethylamino)styryl-1-dococylpyridinium (DMASDPB) could orient on the chiral nanotemplates of DNA in the self-assembled films. UV−vis analysis indicated that these film materials have high transparency from 300 to about 1000 nm. These self-assembled functional-dye-containing DNA−surfactant complex materials, with good processability for multilayer integration into large-area devices, will have promising applications in molecular optical and molecular optoelectronic fields.