An Interfacial‐Assembled Self‐Supporting Nanofilm Induced by Strong Intermolecular Interaction between Silk Fibroin and Lysozyme

Abstract Organic ultrathin nanofilms are increasingly favored in a wide range of applications, including flexible photonics and electronics, smart skin devices, sensing, and bioinspired designs, due to their high flexibility, chemical activity, and stimuli‐responsiveness. To create large‐area, robust, and freestanding nanofilms efficiently, a protein interfacial cooperative assembly technique that utilizes silk fibroin and lysozyme as building blocks is developed. The strong intermolecular interaction between these two proteins, coupled with the abundant intra‐ and intermolecular β‐sheets, confers remarkable mechanical robustness to the nanofilms with thicknesses as low as 50 nm. Consequently, these nanofilms exhibit the unique ability to stand freely in the air and can be conformally transferred to substrates of different types and topographies, forming stable, and versatile nanocoatings. The advantageous attributes of their ultrathinness, large‐scale homogeneity, robustness, and rapid and tunable responsiveness facilitate the construction of ultrasensitive photonic architectures and organic–inorganic hybrid multilayers with outstanding optical and mechanical properties. It is envisioned that these all‐protein‐based robust nanofilms with unique nanoscale effects can be easily integrated into various advanced technological platforms to enable adaptive, multifunctional, and intelligent systems with exceptional mechanical strength.