Residual activities of free enzyme and enzyme immobilized on the most efficiently protecting carrier material (either amino or epoxy-butyl based Lifetech ERC resins (Purolite)) after different plasma treatment times. HRP immobilized on epoxy-butyl based ERC resin. Plasma treatment times of up to 3600 s were used. The specific activity of untreated enzyme was set to 100% activity. Data of free HRP are taken from Yayci et al.. Means and standard deviations of three independent biological replicates are shown.