Contribution of convective flux to uniform apoferritin film formation on a liquid gallium surface

We generated nanometer thin apoferritin films on a liquid gallium surface by drying wetting films of aqueous apoferritin solution, which was formed continuously by expanding the solution. The film formation process had been optically visualized and then analyzed at different protein concentrations and expansion speed. We thus found that protein film formation consisted of protein adsorption to the surface coupled with a convective flux of proteins induced by water evaporation from the wetting film surface. We proved that a convective flux promoted film formation even if the included protein was in the nanometer-scale.