Ionic Liquid-Based Periodic Mesoporous Organosilica: An Innovative Matrix for Enzyme Immobilization

Abstract

Employment of enzyme immobilization technique for α‐amylase, provides useful approaches to improve enzyme resistance to harsh conditions and reusability. Two silica supports, Ionic Liquid‐Based Periodic Mesoporous Organosilica which we call it PMO‐IL, and SBA‐15, have been used for immobilization of α‐amylase. We found that proper electrostatic interactions result in a higher immobilization yield of PMO‐IL rather than SBA‐15. The kinetics parameters show that α‐amylase@PMO‐IL activity has slightly decreased in comparison to free enzyme and the stability studies indicate that it is even more active than free enzyme in the natural pH which shows the improving role of ionic liquid on enzyme structure and function. Also, both immobilized enzymes have 2 times more stability at 70 °C and 80 °C after 60 min in comparison to free enzyme. Finally, the recovery efficiency of α‐amylase@PMO‐IL is 88% of its initial activity after 4 cycles which is 23% more than a previous report.

Ionic Liquids for Development of Heterogeneous Catalysts Based on Nanomaterials for Biocatalysis

“…PMO is an organic–inorganic material, where organic groups are ordered inside the silica’s channel walls. Immobilized amylase on PMO-IL retained 88% of its initial activity after four reaction cycles, and showed two times better thermal stability at 70 °C and 80 °C compared with a native form [ 90 ]. The activity of CALB was examined in the glycerolysis of corn oil for diacylglycerol production.…”

“…Moreover, the porosity of silica nanoparticles increases ionic liquid loading on the surface, and so on the efficiency of enzyme immobilization. The high activity and thermal stability of the enzymes were observed after immobilization on silica-based SILLP or SILLP [ 67 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 ].…”

Synthesis of double-shelled periodic mesoporous organosilica nanospheres/MIL-88A-Fe composite and its elevated performance for Pb2+ removal in water

“…So-called periodic mesoporous organosilica (PMOs) as advanced hybrid organic–inorganic materials have been investigated with great interest owing to their unique physicochemical properties such as porous channels 54 , robust porous organic–inorganic framework 86 , adjustable pore size organization 87 , 88 , biocompatibility 89 , and the highest organic content in the (nano)material 90 . These excellent properties render PMOs attractive for applications in many fields, such as adsorption 47 – 52 , catalysis 91 – 97 , light-harvesting 98 , 99 , electronics 100 – 102 , drug release studies in simulated biological media 103 – 108 , chromatography 109 , enzyme immobilization 110 , 111 , and bactericides 112 , 113 . PMOs have a lot of applications as catalysts in many fields such as the synthesis of dihydropyrano[3,2-c] chromene derivatives 114 , sonogashira reaction 115 , Chan-Lum coupling 116 , condensation of a variety of different aldehydes with malononitrile 117 , Knoevenagel condensation 118 , oxidation of alcohols 119 , 120 , clean production of polyhydroquinolines 121 , and Heck reaction 122 .…”