Residual activity of immobilized HRP after 900 s of plasma treatment. Immobilization was carried out using Lifetech ECR (Purolite) carriers according to the manufacturers' instructions. For HRP, only non-directional resins were used for immobilization, because the enzyme did not have a His-tag. The specific activity of the respective untreated immobilized enzyme was set to 100%. Means and standard deviations of three independent biological replicates are shown.