Novel, self-assembling protein-based biomaterials, including fibers and hydrogels, are computationally designed and assessed for their theranostic properties. Design approaches include the incorporation of non-canonical amino acids and bio-orthogonal conjugation to develop hybrid biomaterials. These theranostic materials have therapeutic capabilities in their ability to house and deliver small hydrophobic drug molecules and diagnostic capabilities in their ability to be used in imaging applications such as MRI.