Protein-Polymer Block Copolymer Self-Assembly

Self-assembly of globular protein-polymer diblock copolymers provides a direct route towards nanopatterning proteins and enzymes at high densities while also preserving high levels of protein activity. By effectively nanopatterning proteins, this technique has the potential to aid in the fabrication of a variety of highly efficient biocatalytic, bioelectronic and biosensor devices. Our block copolymers are synthesized by covalently attaching a single monodisperse polymer to each protein molecule using site-specific chemistry. Self-assembly of these materials is typically induced through solvent evaporation. We utilize a combination of scattering and microscopy techniques to investigate the resulting self-assembled nanostructures in solution, bulk, and thin film samples. The phase behavior of these materials is studied as a function of relative polymer volume fraction, block copolymer concentration in solution, and temperature resulting in a rich variety of structures including cylinders, lamellae, perforated lamellae and disordered micelles.

Within this project area, we are continually exploring the incorporation of new enzymes and polymers into our materials to demonstrate the utility of this approach for nanopatterning a wide range of commercial and scientific applications. In fact, the range of potential applications is limited only by the number of different enzymatically catalyzed reactions. By tuning the chemistry of the polymer block, control may be achieved over the type of nanostructure formed and transport properties through materials can potentially be engineered. While the incorporation of new proteins or polymers will expand the functionality of such devices, it will also alter the solvent mediated interactions driving self-assembly. We are interested in exploring such effects as protein surface chemistry and protein shape on the self-assembly behavior of these types of materials and on developing thermodynamic models for the complex self-assembly process in protein-polymer conjugates.