DIRECT ATOMIC-FORCE MICROSCOPIC EVIDENCE OF HYDROGEN-BONDING INTERACTION IN PHOSPHATIDIC-ACID LANGMUIR-BLODGETT BILAYER

Molecularly resolved atomic force microscopic images of phosphatidic a cid Langmuir-Blodgett bilayers show that phosphate groups in polar reg ion of the films are packing in a distorted hexagonal organization wit h long-range orientational and positional order. Intermolecular hydrog en bonding interactions, which should be responsible for the ordering and stability of bilayers, are visualized directly between adjacent ph osphate groups in the polar region of the bilayer. Some adjacent phosp hatidic acid molecules link each other through the formation of interm olecular hydrogen bonds between phosphate groups in polar region to fo rm local supramolecules, which provide the bilayer's potential as a fu nctionized film in the investigation on the lateral conductions of pro tons in the biological bilayers. (C) 1997 Elsevier Science B.V.