Determination of Lipid Phase Transition Temperatures in Hybrid Bilayer Membranes
Neil A. Anderson, Lee J. Richter, John C. Stephenson, Kimberly A. Briggman
The main gel to liquid crystal (LC) phase transition temperature, Tm, of the lipid monolayers in hybrid bilayer membranes (HBMs) was investigated using vibrational sum frequency spectroscopy (VSFS). The unique sensitivity of VSFS to probe order/disorder transitions was used to determine Tm for a series of saturated phosphatidylcholines on octadecanethiolate self assembled monolayers (SAMs). The values obtained for Tm average 10 degrees C higher for the lipids in HBMs than for the corresponding lipids in vesicles in solution.