The Effect of Monolith Properties on the Digestion Performance of Monolith-Based Immobilized Enzyme Microreactor

In this work, two kinds of monolith-based immobilized enzyme microreactors (IMER) were compared in terms of monolith properties and digestion performance. Two monoliths were prepared involving poly (tetraethoxysiLane-co-3-aminopropyltriethoxysilane) (poly (TEOS-co-APTES)) monolith and poly (N-acryloxysuccinimide-co-acrylamide-co-ethylene dimethacrylate) (poly (NAS-co-AA-co-EDMA)) monolith for covalent trypsin immobilization. A higher chromatographic permeability constant 66.7 was obtained from the poly (TEOS-co-APTES) monolith in comparison with only 4.37 for poly (NAS-co-AA-co-EDMA) monolith, and the porous property of monolith measured by N2 adsorption/desorption and mercury intrusion porosimetry also indicated that poly (TEOS-co-APTES) monolith has more pores than poly (NAS-co-AA-co-EDMA) monolith. On the other hand, the digestion results demonstrated that the more efficient IMER was obtained by immobilizing trypsin on the poly (TEOS-co-APTES) monolith even if a less amount of immobilized trypsin determined by the Bradford method than poly (NAS-co-AA-co-EDMA) monolith. Therefore, the capacity of trypsin immobilization of monolith was not the exclusive factor to determine the digestion performance of IMER. Physical properties-penetrability and pore distribution of monolith showed a crucial effect on the digestion performance of IMER.