Deposition of pepsin thin layer using IR-MAPLE procedure

Nowadays significant interest turned towards the thin layers of large organic molecules due to their applicability in medicine and biosensor fabrication. Matrix assisted pulsed laser evaporation (MAPLE) is a promising technique for thin layer preparation in the cases of sensitive biomaterials. An obviously natural, inert matrix material would be the water, i.e. ice for solid target. However its absorption coefficient in wavelength range of the mostly used, ultraviolet lasers is relative low, a few 1/m. Therefore in our experiments beam of a CO₂ laser was used to ablate an enzyme solved in water showing strong absorptivity in far-IR. Our main aim was to demonstrate that the IR-MAPLE is suitable for the deposition of biologically active pepsin thin layer from frozen pepsin-water matrix solution. Our experiments demonstrated that the IR-MAPLE method is suitable for the deposition of thin layers from sensitive biomaterials using water as matrix material.