Encapsulation of Microperoxidase-8 in MIL-101(Cr)-X Nanoparticles: Influence of Metal–Organic Framework Functionalization on Enzymatic Immobilization and Catalytic Activity

Abstract

Microperoxidase 8 (MP8) was immobilized within MIL-101(Cr) bearing terephthalate linkers with functionalized groups (-NH 2 and -SO 3 H). A synthesis protocol for MIL-101(Cr)-SO 3 H that avoids the use of toxic Cr(VI) and HF was developed. The electrostatic interactions between the MP8 molecules and the MOF matrices were found to be crucial for a successful immobilization. Raman spectroscopy revealed the dispersion of the immobilized MP8 molecules in MIL-101(Cr)-X matrices as monomers without aggregation. The presence of functional groups resulted in higher amounts of immobilized MP8 in comparison to the bare MIL-101(Cr). The catalytic activity of MP8@MIL-101(Cr)-NH 2 per material mass was higher than for MP8@MIL-101(Cr).The presence of free amino groups can thus improve the immobilization efficiency, leading to higher amount of catalytic active species and improving the subsequent catalytic activity of the heterogeneous biocatalysts. MP8@MIL-101(Cr)/-NH 2 successfully catalyzed as well the selective oxidation of thioanisole derivatives into sulfoxides.

Green Synthesis of Porous Spherical Reduced Graphene Oxide and Its Application in Immobilized Pectinase

“…In addition, in a pH range of 3.0–6.0, the relative activity of immobilized pectinase was greater than that of free pectinase. It means that the scope of pH stability of immobilized pectinase is significantly expanded …”

“…It means that the scope of pH stability of immobilized pectinase is significantly expanded. 34 The optimum temperature for free and immobilized pectinases is shown in Figure 7b. The optimum temperature for both types of pectinase was 45 °C.…”

The Chemistry and Applications of Metal–Organic Frameworks (MOFs) as Industrial Enzyme Immobilization Systems

“…The number of biomedical applications of structures based on MOFs has been growing throughout the years due to the excellent versatility of these materials, high porosity, and large available surface area [ 132 ]. One of these key applications is in drug loading, which allows MOFs to work as carriers of the active compounds of various drugs through the body, from small organic molecules to macromolecules, such as nucleic acids and proteins ( Figure 7 ) [ 180 ]. One issue related to this application is the toxicity of MOFs and the materials’ lack of full biocompatibility with the organism [ 181 ].…”

Recent Advances in Emerging Metal– and Covalent–Organic Frameworks for Enzyme Encapsulation

“…Moreover, the dimensions of the enzyme molecule can be larger than the pore channel of MOFs, leading the enzymes to be surrounded by frameworks. In situ and pore encapsulation was employed in mesoporous MOFs and COFs (Fe-ZIF8, 37 COF-43-B, 38 Zn-MOF, 39 PCN-222(Fe), 40 MIL-88B, 41 H-MOF(Zr), 42 MIL-101(Cr), 43 Cu-BTC-based MOF, 44 Pd@ED-MIL-10, 45 PW@MIL-100(Fe), 46 Tb-MOF, 47 meso-MIL-53(Al), 48 COF-OMe, 49 etc. ), which is an efficient strategy to protect enzymes from harsh conditions by isolating enzyme molecules in the pores of the organic framework as well as preventing enzyme leakage from the supports.…”