Production of active lysozyme films by matrix assisted pulsed laser evaporation at 355 nm

Thin lysozyme films have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix irradiated by laser light at 355 nm above the absorption threshold of the protein. A significant part of the lysozyme molecules are transferred to the film without decomposition and the protein activity is preserved. The film deposition rate for 1 wt% lysozyme shows a clear maximum of about 1 ng/cm2 per shot for a moderate fluence of 2 J/cm2, which is about one-half of the deposition rate from a pressed (100%) lysozyme target.