Conformal epoxy-rich coatings are synthesized by plasma initiated chain-growth polymerization of glycidyl methacrylate via a newly developed Plasma initiated chemical vapor deposition method at atmospheric pressure to provide a functional platform for the immobilization of enzymes degrading antibiotics (laccase and β-lactamase). In addition to enhance the enzymes activity duration and intensity, surface immobilization is also leading to enzyme structure rigidification, allowing them to endure mechanical stresses generated by a laminar water flow of 30 km h−1, and this with no reduction of their enzymatic activity. Self-defensive surface properties against microorganism's adhesion, preventing the enzyme alteration and improving the degradation performances, are obtained via surface saturation with Tween 20. The developed method is scaled up to high specific surface high-density polyethy­lene biochips commonly used in water treatment, and shows self-defensive abilities and particularly long lasting efficient degradation properties.