Biomimetic fabrication of genetically engineered collagen peptide-assembled freestanding films reinforced by quantum dot joints

Genetically engineered collagen peptides were assembled into freestanding films when QDs were co-assembled as joints between collagen domains. These peptide-based films show excellent mechanical properties with Young's modulus of ∼20 GPa, much larger than most of the multi-composite polymer films and previously reported freestanding nanoparticle-assembled sheets, and it is even close to that reported for the bone tissue in nature. These films show little permanent deformation under small indentation while the mechanical hysteresis becomes remarkable when the load approaches near and beyond the rupture point, which is also characteristic of the bone tissue.