This invention provides a method of irreversibly immobilizing an enzyme into polyurethane coatings. This invention also provides for an enzyme-containing coating having a degree of immobilization of the enzyme of approximately 100%. The synthesis of waterborne polyurethane coatings in the presence of enzyme has enabled the irreversible attachment of the enzyme to the polymeric matrix. The distribution of immobilized enzyme as well as activity retention are homogeneous within the coating. Decreasing ECC hydrophobicity, via the use of a less hydrophobic polyisocyanate prepolymer during polymerization, significantly enhanced the intrinsic activity of the ECC.