The discovery of a general strategy for
organizing functional proteins into stable nanostructures
with the desired dimension, shape, and function is an
important focus in developing protein-based self-assembled
materials, but the scalable synthesis of such materials and
transfer to other substrates remain great challenges. We
herein tackle this issue by creating a two-dimensional
metal−protein hybrid nanofilm that is flexible and costeffective
with reliable self-recovery, stability, and multifunctionality.
As it differs from traditional metal ions, we
discover the capability of Sn2+ to initiate fast amyloid-like
protein assembly (occurring in seconds) by effectively
reducing the disulfide bonds of native globular proteins.
The Sn2+-initiated lysozyme aggregation at the air/water interface leads to droplet flattening, a result never before
reported in a protein system, which finally affords a multifunctional 2D Sn-doped hybrid lysozyme nanofilm with an
ultralarge area (e.g., 0.2 m2) within a few minutes. The hybrid film is distinctive in its ease of coating on versatile material
surfaces with endurable chemical and mechanical stability, optical transparency, and diverse end uses in antimicrobial and
photo-/electrocatalytic scaffolds. Our approach provides not only insights into the effect of tin ions on macroscopic selfassembly
of proteins but also a controllable and scalable synthesis of a potential biomimic framework for biomedical and
biocatalytic applications.