College of Chemical Engineering, Integrated Nanocatalysts Institute (INCI), Academy of Advanced Carbon Conversion Technology, Huaqiao University, 668 Jimei Avenue, Xiamen, Fujian 361021, P. R. China.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):35552-35564. doi: 10.1021/acsami.3c07088. Epub 2023 Jul 12.
Metal-organic frameworks (MOFs) have become promising host materials for enzyme immobilization and protection. Herein, ZIF-8 nanocubes were successfully self-assembled onto yeast as a biological template to obtain hybrid Y@ZIF-8. The size, morphology, and loading efficiency of ZIF-8 nanoparticles assembled on yeast templates can be well-regulated by adjusting the various synthetic parameters. Particularly, the amount of water significantly affected the particle size of ZIF-8 assembled on yeast. Through using a cross-linking agent, the relative enzyme activity of Y@ZIF-8@t-CAT could be greatly enhanced and remained the highest even after seven consecutive cycles, with improved cycling stability, as compared to that of Y@ZIF-8@CAT. In addition to the effect of the physicochemical properties of Y@ZIF-8 on the loading efficiency, the temperature tolerance, pH tolerance, and storage stability of Y@ZIF-8@t-CAT were also systematically investigated. Importantly, the catalytic activity of free catalase was decreased to 72% by 45 days, while the activity of the immobilized catalase remained above 99%, suggesting good storage stability. The present work demonstrates that yeast-templated ZIF-8 nanoparticles have a high potential to be used as biocompatible immobilization materials and are promising candidates for the preparation of effective biocatalysts in biomedicine applications.
金属有机骨架（MOFs）已成为酶固定化和保护的有前途的宿主材料。在此，ZIF-8 纳米立方体形成功地自组装到酵母上作为生物模板，以获得混合 Y@ZIF-8。通过调整各种合成参数，可以很好地调节组装在酵母模板上的 ZIF-8 纳米颗粒的尺寸、形态和负载效率。特别是，水的量显著影响了组装在酵母上的 ZIF-8 颗粒的尺寸。通过使用交联剂，可以大大提高 Y@ZIF-8@t-CAT 的相对酶活性，并且即使在连续七次循环后，其活性仍保持最高，与 Y@ZIF-8@CAT 相比，其循环稳定性得到了改善。除了 Y@ZIF-8 的物理化学性质对负载效率的影响外，还系统地研究了 Y@ZIF-8@t-CAT 的温度耐受性、pH 耐受性和储存稳定性。重要的是，游离过氧化氢酶的催化活性在 45 天后下降到 72%，而固定化过氧化氢酶的活性仍保持在 99%以上，表明其具有良好的储存稳定性。本工作表明，酵母模板化 ZIF-8 纳米粒子具有作为生物相容的固定化材料的高潜力，并且是在生物医学应用中制备有效生物催化剂的有前途的候选物。
