Synthesis and Electro-Optical Properties of a Novel DNA–Lipid Complex Carrying Carbazole Moieties

摘要

A novel DNA–lipid complex carrying carbazole (Cz) moieties was prepared by substituting the sodium counter cation with cationic lipid, namely lipid(2Cz), in which the actual mole ratio of phosphate to lipid was 1:1.05. The DNA–lipid(2Cz) complex was soluble in common organic solvents including CHCl₃, CH₂Cl₂, methanol, and ethanol, while insoluble in THF, toluene, and water. CD spectroscopy revealed that the DNA–lipid complex took a predominantly double helical structure in methanol and that the helical structure was fairly stable against heating. A solution of the DNA–lipid(2Cz) complex emitted fluorescence in 40.0% quantum yield, which was lower than that of the corresponding lipid(2Cz) (76%). The cyclic voltammograms of the complex indicated that the oxidation potential of DNA–lipid(2Cz) was 0.65 V. The onset temperature of weight loss of the DNA–lipid complex is 230 °C according to TGA in air.