Electrospun polyacrylonitrile-glycopolymer nanofibrous membranes for enzyme immobilization

A biocatalyst was fabricated by the covalent immobilization of the enzyme catalase on a polyacrylonitrile (PAN) based nanofibrous membrane incorporating a glycopolymer. The glycopolymer poly-(6-O-vinylsebacoyl d-glucose) [poly-OVSEG] was synthesized by a water phase precipitation homopolymerization process, and its structure was characterized by Fourier transform infrared spectroscopy (FT-IR) and NMR. Composite membranes of PAN/poly-OVSEG nanofibers containing varying amounts (50–70%) of poly-OVSEG were subsequently prepared using electrospinning. The nanofibers were studied by scanning electron microscopy (SEM) and FT-IR. Their hydrophilicity was investigated by measuring water contact angles. With increasing content of poly-OVSEG, the contact angle decreases from 65.5 ± 2.5° to 15.2 ± 1.1°. Catalase was immobilized on the composite nanofibrous membranes by covalent binding. The maximum catalase adsorption capacity of the polyacrylonitrile-based nanofibrous membranes was observed to be ca. 46.5 mg/g. Over 50% of catalyst activity was retained and increased thermal stability observed post-immobilization (with maximum activity at pH 7.5 and 50 °C). This study demonstrates the potential of using electrospun membranes to improve the thermal and storage stabilities of biological catalysts.