金属有机框架固定化漆酶的制备及其对邻苯二酚的降解

Preparation of Immobilized Laccase onto Framework-like Material of Metal-organic Compound and Its Degradation for Catechol

以金属有机框架材料(ZIF-90)为固定载体,采用内部封装和表面物理吸附两种方法固定漆酶(LAC),分别制备出LAC@ZIF-90和LAC-ZIF-90复合材料,使用扫描电镜(SEM)、激光共聚焦显微镜(CLSM)、X射线衍射(XRD)、傅里叶红外变换光谱(FT-IR)以及荧光分析等手段分析漆酶固定前后的结构和性能,对比分析了游离漆酶和固定漆酶的使用稳定性,根据高效液相色谱(HPLC)研究了固定化漆酶对邻苯二酚的降解性能。结果表明:漆酶分子固定在ZIF-90的表面和内部,分子结构稳定。在最适当的pH值条件下,LAC-ZIF-90和LAC@ZIF-90震荡6 h对邻苯二酚的去除率分别为97%和19.4%。LAC-ZIF-90和LAC@ZIF-90经过5次重复使用后仍具有较高的活力,LAC-ZIF-90重复5次后对邻苯二酚的去除率仍高于78%。

Laccase(LAC)was immobilized onto a framework-like material of metal-organic compound(ZIF-90)by means of internal encapsulation and surface physical-adsorption,herewith,two composites of LAC@ZIF-90 and LAC-ZIF-90 were prepared respectively.The structure,property,stability and degradation performance for catechol of the free-and immobilized-laccase were comparatively characterized by means of scanning electron microscopy(SEM),laser confocal electron microscopy(CLSM),Xray diffractometer(XRD),Fourier transform infrared spectroscopy(FT-IR),fluorescence analysis and high performance liquid chromatography(HPLC)etc.The results show that:laccase molecules were fixed on the surface and inside of ZIF-90,and the molecular structure was stable before and after being fixed;the removal rates for catechol by lac-ZIF-90 and LAC@ZIF-90 were 97%and 19.4%,respectively for the solution with proper pH value,whilst by vibrating for 6 h;the lac-ZIF-90 and LAC@ZIF-90 still showed high vitality after repeatedly used for 5 times;it is especially worthy that the removal rate of catechol was higher than 78%even after repeatedly used for 5 times for the lac-ZIF-90.