Micellization of glucose-based surfactants with different counter ions and their interaction with DNA

The sugar surfactants are a relatively new class of surfactants. So far, although there have been a number of reports about their syntheses, the studies about their physical chemical properties and their interaction with DNA have been limited. In the present paper, we synthesized three glucosylammonium surfactants, with the same hydrophobic alkyl chain (dodecyl) and different counter ions (propanedioate, succinate and adipate). We found that these three surfactants could decrease the surface tension of water to ca. 30 mN/m and the counter ions played an important role in the surfactant aggregation. The surfactant with propanedioate as the counter ion has the greatest preference to be adsorbed at water/air surface, while the surfactant with succinate as the counter ion has the lowest critical micelle concentration. Moreover, the surfactant with propanedioate as the counter ion interacts with DNA strongest and that with adipate as the counter ion interacts with DNA weakest. In addition, the sugar moiety of the surfactant can shield the surface charge of the surfactant/DNA aggregates very effectively; ζ potential for the DNA/glucosylammonium surfactant is ca. 20 mV (which is usually higher than 40 mV for DNA/cationic surfactant aggregates).