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 ii 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 degreesC, Thermodynamical analysis indicated that these film materials were thermo-extensive over a temperature range from 100 to 148 degreesC, 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 4[4-(dimethylamino)styryl]-1-dococylpyridinium (DMASBPB! 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.