Activity of enzymes immobilized on plasma treated polyester

[Display omitted] •β-galactosidase was immobilized on plasma activated nonwoven PET without toxic reagents.•Air atmospheric plasma and CRP plasma using N2 and N2/O2 gases were used.•Enzyme entrapped in alginate film fixed on PET fiber surface maintained its activity.•Greater amount of enzyme was immobilized by the sorption method.•Adsorbed enzyme lost their activity, but activity reached 90% with the CRP N2/O2 plasma. The aim of this study was to investigate the effect of 3 different surface plasma treatments on the immobilization of β-galactosidase on a fibrous PET nonwoven membrane. Two methods 1. Entrapment in a thin calcium alginate coating and 2. Direct sorption, were used to immobilize the enzyme. The three different plasma treatments for surface activation of PET nonwovens were: 1. Air atmospheric DBD plasma, 2. Cold remote plasma-CRP with 100% N2 and 3.- CRP with a mixture of N2/O2 gases. Plasma treatment of the PET fiber surface increased the quantity of immobilized enzyme using the entrapment method, and the degree of alginate film cross-linking highly influenced the enzyme activity. Highest enzyme activity was reached for the PET treated with air atmospheric plasma and cross-linked with 0.25g/l of CaCl2. With the direct sorption method, greater amounts of enzyme were immobilized as compared to the entrapment method, but a considerable proportion of enzyme lost their catalytic activity. Only with the CRP N2/O2 plasma treatment, up to 90% of sorbed enzyme maintained their activity. Reusability study showed that for the optimized entrapment method, a progressive decrease in activity was observed after each use cycle. With the optimized sorption method using N2/O2 CRP plasma, no decrease in enzyme activity was detected, and the immobilized enzyme could be used over more than 15 cycles.