Ordered Arrays of Amphiphilic Gold Nanoparticles in Langmuir Monolayers

Large ordered arrays of gold nanoparticles with 1.4 nm cores were created in Langmuir monolayers from an amphiphilic starting material, Palmitoyl Nanogold. Transfer of the films to transmission electron microscope grids by the Langmuir−Schaeffer method resulted in observation of highly ordered hexagonal arrays larger than 250 × 350 nm2. The application of sustained pressure increased the size of ordered regions over those observed immediately after compression. Our work demonstrates ordered arrays with particles that are smaller than those that have been successfully ordered previously in Langmuir layers. The amphiphilic nature of the particles assists in maintaining a monolayer during compression.