Insertion process of a protein single layer within a Newton black film

We report a generally applicable protein insertion process leading to the formation of a close packed protein single layer within a freestanding surfactant bilayer. Very high packing fractions can be obtained in a controlled manner, simply by adjusting the protein chemical potential in the solution. We apply this method to the confinement of a model protein in a Newton black film (NBF) of a non-anionic surfactant. Using x-ray reflectivity, we observed a time dependent insertion of the proteins within the NBF and then a stable equilibrium state.