First-Principles Determination of Hybrid Bilayer Membrane Structure by Phase-Sensitive Neutron Reflectometry

摘要: The application of a new, phase-sensitive neutron reflectometry method to reveal the compositional depth profiles biomimetic membranes is reported. Determination complex reflection amplitude allows related scattering length density (SLD) profile be obtained by first-principles inversion without need for fitting or adjustable parameters. SLD so unique most and can therefore directly compared with corresponding chemical film, as predicted, example, molecular dynamics simulation. Knowledge real part amplitude, in addition enabling inversion, makes it possible assign spatial resolution given range wavevector transfer over which reflectivity data are collected. Furthermore, imaginary used sensitive diagnostic tool recognizing existence certain in-plane inhomogeneities sample. Measurements demonstrating practical realization this technique were performed on hybrid bilayer membrane (self-assembled monolayer thiahexa (ethylene oxide) alkane gold phospholipid layer) intimate contact an aqueous reservoir. Analysis experimental results shows that accurate now subnanometer range, primarily limited background originating from reservoir roughness film's supporting substrate.