Electrochemical and PM-IRRAS characterization of DMPC + cholesterol bilayers prepared using Langmuir–Blodgett/Langmuir–Schaefer deposition

Differential capacitance, chronocoulometry and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) measurements were used to characterize the structure and orientation of DMPC + cholesterol (70:30 mol%) phospholipid bilayers prepared using combined Langmuir–Blodgett/Langmuir–Schaefer (LB/LS) deposition. The electrochemical measurements indicate that incorporation of cholesterol into the membrane improves the quality of the bilayer if both leaflets contain cholesterol. Phospholipid bilayers containing DMPC and cholesterol prepared using LB/LS deposition were found to have smaller tilt angles (∼27°) than bilayers prepared by vesicle spreading (∼52°), indicating that LB/LS deposition is a superior method for preparing supported phospholipid bilayers at a gold electrode surface.