Nanoscale stripe patterns in phospholipid bilayers formed by the Langmuir-Blodgett technique

A new methodology has been developed to create an extensive pattern of parallel stripes, similar to150-250 nm wide, in phospholipid bilayers supported on mica. These striped bilayers are prepared by the Langmuir-Blodgett (LB) film technique. A striped monolayer consisting of two phospholipids in different states (condensed and liquid-expanded) is used to direct the deposition of the solid- and liquidlike phases of a second mixed monolayer during LB transfer. We also demonstrate that bilayer stripes can be generated by the condensation of phospholipids over the solidlike stripe domains of the underlying monolayer for a one-component film deposited just below the liquid-expanded-to-liquid-condensed phase transition pressure. Nonionic detergent extraction of the liquidlike phase from these LB films resulted in bilayer-thick phospholipid stripes separated by a mica surface. A periodic array of grooves was produced by the selective adsorption of protein onto the mica regions of the detergent-treated bilayer. The LB film deposition of binary mixtures of solid-phase- and fluid-phase-forming phospholipids constitutes a novel strategy to create linear surface patterns that can be used to direct the deposition of molecules.