Functionalized ionic liquid modified mesoporous silica SBA-15: a novel, designable and efficient carrier for porcine pancreas lipase

A series of functionalized ionic liquid modified mesoporous silicas SBA-15 (FIL-SBA) were synthesized by modulating the loading and cation/anion ratio of the functionalized ionic liquid (FIL). The prepared materials FIL-SBA were used as a novel carrier system to immobilize porcine pancreas lipase (PPL). Enzymatic activity and reusability of the immobilized enzyme were investigated using the triacetin hydrolysis reaction. The combined advantages of the nano-sized pore diameter, large surface area and high pore volume of SBA-15, and the tunable properties of the FIL for enzymes immobilized in FIL-SBA gave a maximum improvement of 570% in relative activity, with 63% retention of initial activity after five cycles of use. Carriers and immobilized enzymes were characterized using nitrogen adsorption, small-angle X-ray diffraction (SXRD), Fourier transform infrared (FT-IR), elemental analysis, nuclear magnetic resonance (NMR), scanning and transmission electron microscopy (SEM and TEM). It was shown that the introduction of FIL influenced the catalytic behavior of PPL significantly by changing the structure and surface properties of the carriers.