Immobilization of alpha-chymotrypsin on oxygen-RF-plasma functionalized PET and PP surfaces.

In this contribution the immobilization of alpha-chymotrypsin on plasma activated PET and PP surfaces is investigated. The 'anchoring' C=O groups on polymer surfaces were created under RF-O2-plasma environments. The identity and relative concentrations of plasma-created functionalities were evaluated using survey and high resolution X-ray photoelectron spectroscopy, and differential attenuated total reflectance-FTIR spectroscopy. Surface morphology changes of plasma-exposed substrates were analyzed by atomic force microscopy. Enzyme assays were performed from both virgin and plasma modified samples which underwent the immobilization procedure. It was demonstrated that cold-plasma technique is suitable for generating functional, synthetic polymeric surfaces which can initiate enzyme coupling reactions. It also has been shown that the activity of the immobilized enzyme is lower in comparison to the free enzyme. Reduced conformational mobility resulting from multiple-point coupling process might be responsible for this behavior.