<p>Enzymatic catalysis has been widely applied in chemical processes due to its high selectivity and mild reaction conditions. Proteases and lipases are key industrial enzymes, particularly in food and detergent applications, where their immobilization on suitable supports enhances stability and reusability. In this study, we investigated the efficiency of protease and lipase immobilization on biodegradable nano-polymers using a sandwich-structured system. Polyvinyl alcohol (PVA) and starch were blended to form a stable and homogeneous base layer, which showed no phase separation or degradation during storage at room temperature. A polyurethane (PU) surface layer was applied to improve thermal resistance, while the PVA–starch layer provided an eco-friendly and biodegradable matrix for enzyme fixation. Heat treatment of the PVA–starch layer further increased immobilization efficiency. Compared with conventional methods such as covalent binding or encapsulation, this sandwich-structured approach offered enhanced enzyme stability, controlled release, and biodegradability, making it a promising strategy for sustainable detergent formulations.</p>