Nanoscaled Biocoatings via Enzyme Mediated Autodeposition of Casein

Formation of nanoscaled monolayer protein structures via enzyme mediated autodeposition is investigated on the example of casein as protein and chymosin as enzyme. The key of this method is tethering of enzyme to the support. This ensures that destabilization and subsequent deposition of casein particles occurs only in direct proximity to the support surface. In this work, covalent enzyme coupling (with and without polymeric spacer) is applied to obtain high site-specificity and self-terminating properties of the autodeposition process. Direct covalent coupling results in defined deposition of monolayer films or single particles. Use of polymeric spacers increases the amount and radius of deposition by a factor of 4, due to higher mobility of enzyme and delayed self-termination. Deposited casein structures show qDMT-moduli of 1.2-1.4 GPa, indicating higher flexibility compared to conventional casein coatings. Applications might arise in the fields of implantology and biosensor technology as well as renewable coatings.