Amino Functionality Enables Aqueous Synthesis of Carboxylic Acid-Based MOFs at Room Temperature by Biomimetic Crystallization

Inorg Chem. 2024 May 27;63(21):9801-9808. doi: 10.1021/acs.inorgchem.4c00245. Epub 2024 May 14.

Abstract

Enzyme immobilization within metal-organic frameworks (MOFs) is a promising solution to avoid denaturation and thereby utilize the desirable properties of enzymes outside of their native environments. The biomimetic mineralization strategy employs biomacromolecules as nucleation agents to promote the crystallization of MOFs in water at room temperature, thus overcoming pore size limitations presented by traditional postassembly encapsulation. Most biomimetic crystallization studies reported to date have employed zeolitic imidazole frameworks (ZIFs). Herein, we expand the library of MOFs suitable for biomimetic mineralization to include zinc(II) MOFs incorporating functionalized terephthalic acid linkers and study the catalytic performance of the enzyme@MOFs. Amine functionalization of terephthalic acids is shown to accelerate the formation of crystalline MOFs enabling new enzyme@MOFs to be synthesized. The structure and morphology of the enzyme@MOFs were characterized by PXRD, FTIR, and SEM-EDX, and the catalytic potential was evaluated. Increasing the linker length while retaining the amino moiety gave rise to a family of linkers; however, MOFs generated with the 2,2'-aminoterephthalic acid linker displayed the best catalytic performance. Our data also illustrate that the pH of the reaction mixture affects the crystal structure of the MOF and that this structural transformation impacts the catalytic performance of the enzyme@MOF.

MeSH terms

  • Amines / chemistry
  • Biomimetic Materials / chemical synthesis
  • Biomimetic Materials / chemistry
  • Carboxylic Acids* / chemistry
  • Catalysis
  • Crystallization*
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Metal-Organic Frameworks* / chemical synthesis
  • Metal-Organic Frameworks* / chemistry
  • Molecular Structure
  • Phthalic Acids / chemistry
  • Temperature*
  • Water* / chemistry
  • Zinc / chemistry

Substances

  • Metal-Organic Frameworks
  • Carboxylic Acids
  • Water
  • Phthalic Acids
  • terephthalic acid
  • Zinc
  • Enzymes, Immobilized
  • Amines