Patent ID: 8741152

Claim:
A fabrication method for a protein membrane, which is a flexible free-standing thin membrane, the method comprising: (1) keeping a dilute metal (Cd, Cu or Zn) nitrate or chloride solution under neutral or weak basic pH to form spontaneously metal (Cd, Cu or Zn) hydroxide nanostrands whose diameters are 2-3 nm; (2) mixing the metal (Cd, Cu or Zn) hydroxide nanostrands and protein solution thereby obtaining a dispersion of composite nanofibers made of protein and the metal (Cd, Cu or Zn) hydroxide nanostrands; (3) filtering the dispersion of the composite nanofibers on a filter; (4) cross-linking the protein contained in the composite nanofibers by a bifunctional cross-linker thereby obtaining a cross-linked nanofibrous composite film; and (5) removing the metal (Cd, Cu or Zn) hydroxide nanostrands with the diameters of 2-3 nm from the cross-linked nanofibrous composite film thereby obtaining a flexible free-standing thin protein membrane containing channels.