Solvent-assisted patterning of polyelectrolyte multilayers and selective deposition of virus assemblies.

We introduce a simple method to pattern electrostatic assemblies of viruses onto a polyelectrolyte multilayer. The increased mobility of weak polycation chains in the multilayer above a given thickness ensures the surface mobility of viruses required for spontaneous ordering of densely packed viruses atop polymeric patterns. To pattern the polyelectrolyte multilayer film, we employ a nonconventional patterning method known as solvent-assisted capillary molding for the first time on multilayer films, and demonstrate micrometer-scaled dense patterns of viruses, where the accessible feature size can be correlated by the length scale of virus and swelling property of underlying patterned polyelectrolyte multilayer. We further examine the ability to modify the top surfaces of these assemblies with biological ligands, which extends the applicability of patterned viruses to biological detection purposes. We expect that the present method described here can be generally applied to the patterning of other polyelectrolyte multilayers and combined with the ordered assembly of anisotropic nanomaterials such as polymeric nanotubes or inorganic nanowires for a broad range of applications.