UiO-66-NH2@PMAA: A Hybrid Polymer-MOFs Architecture for Pectinase Immobilization

A hybrid polymer MOFs architecture UiO-66-NH2@PMAA was synthesized by tethering polymethacrylic acid (PMAA) onto the surface of the metal-organic frameworks UiO-66-NH2, and it was further employed for pectinase immobilization by electrostatic interactions. The hybrid architecture was prepared through a combination of atom transfer radical polymerization (ATRP), click chemistry and postsynthetic modification (PSM). The optimal immobilization parameters were at 25 degrees C and pH 4.0 with 10 U/niL of pectinase for 2 h, under which pectinase showed the highest enzymatic activity (1.21-5 U/mg) and protein loading (448.5 mg/g), respectively. Compared with free pectinase, the immobilized was found to exhibit higher pH, thermo, and storage stability. Additionally, the immobilized pectinase had remarkable reusability, the residual activity reached as high as 81% after 8 cycles continuously. Meanwhile, the desorption of immobilized pectinase can be achieved by changing pH values of the medium. Obviously, the UiO-66-NH2@PMAA with attractive properties is highly promising for enzyme immobilization.