Uticaj anjona, pufera i detergenata na topologiju i morfologiju ZIF-8 kristalita

Abstract

Metal-organic frameworks (MOFs) are a class of inorganic materials with potential application in gas adsorption, biosensitization, biocatalysis, and drug delivery [1]. Zeolitic imidazolate frame-works (ZIFs) are a subclass of MOFs, particularly suitable for enzyme immobilization by biomi-metic mineralization [1]. ZIF-8 consisting of tetrahedral Zn(II) ions bridged via 2-methylimidazole ligands (mIM) is most commonly used for this purpose. However, the topology and morphology of ZIF-8 crystals vary depending on the experimental synthesis conditions. In addition, during the process of biomimetic mineralization, the biocomposite composed of the enzyme immobilized in ZIF-8 is washed with buffers and detergents to remove excess of an adsorbed enzyme, which can lead to the chemical transformation of the surface and undesirable release of the enzyme. There-fore, the influence of anion nature on the topology and morphology of ZIF-8 was investigated in this work, and the stability of ZIF-8 crystallites was tested in acetate buffer (0.1 M; pH = 5.5) and sodium dodecyl sulfate solution (ω = 10%). Crystal morphology was monitored by scanning elec-tron microscopy, while topology was determined using powder X-ray diffraction.