|Martin Neebe1 and Norbert Hampp1,2
1Department of Chemistry, Philipps-University, Hans-Meerwein-St., D-35032 Marburg, Germany, and
Bacteriorhodopsins (BR) are multi-valent materials which allow to produce optical security features comprising three integrated levels for authentification. Photochromic color change of BR is the first level feature which may be tested by the user without any technical equipment required. Polarization-sensitive data storage in BR-layers is used as a typical second level feature. Terminals are necessary to read-out and reconstruct the data stored. The molecular coding of BR is employed to realize traceability of the material. The introduced changes in the gene sequence are dedicated to forensic detection by challenging mass spectrometry methods. The integration of three different security features on a molecular level is unique. Methods have been developed to process the BR-material into inks and laminates which can be used in different products. Field tests which last for up to one year have shown that the BR-based features can be used in daily life by non-trained people.