Synthesis and Characterization of SAMs and Tethered Bilayer Membranes from Unsymmetrically Substituted 1,2-Dithianes

摘要

The synthesis of a series of new membrane-forming compounds,based on previously established components used in an ion-channel switch(ICS) biosensor(Nature 1997,387,580) is described.All new compounds are derived from 4,5-dihydroxy-l,2-dithiane,and contain a hydrophilic reservoir section(based on ethylene glycol units) and a lypophilic section(based on the natural lipid phytanol).Ellipsometry and contact angle measurements indicate that self-assembled monolayers(SAMs) formed from the new materials possess thicknesses and membrane packing comparable to previously reported biosensor components.Tethered bilayer lipid membranes(t-BLMs) incorporating the novel materials were studied using impedance spectroscopy with the ion-carrier valinomycin.The electrical behavior and calculated membrane thickness of the t-BLMs are comparable to those derived from the standard ICS components and this demonstrates that the novel membrane-forming compounds form stable membranes that are sufficiently fluid to transport potassium ions in the presence of valinomycin.