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 DMT‐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.

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The enzyme-mediated autodeposition on the example of casein is reviewed, and deposition of casein structures is investigated in relation to applied immobilization methods of enzyme. First, casein is described in detail with respect to its structure in aqueous environments, followed by presentation of historical and current nonfood applications of casein. The presented process uses enzymes to trigger deposition of bio-based particles in close proximity to a support surface and allows for a high control over film formation and site-specificity. This is ensured by immobilization of enzyme on the support material. The herein described system is based on casein as protein and chymosin as enzyme. Different immobilization methods are investigated with respect to obtainable casein coatings, layers, and structures. Physical adsorption of enzyme enables the formation of casein coatings with controllable film thickness and is suitable for in situ buildup of adhesive layers due to diffusion of enzyme. The highest control over film formation is provided by covalent attachment of enzyme. Based on the attained results, the enzymemediated autodeposition gives new insights into biological material design. Graphical abstractEnzyme Casein micelle intact Bulk zone (no enzyme) Reaction zone Phe Met Support Support Casein micelle cleaved