Abstract:
Laccase is capable of catalyzing a vast array of reactions, but its low redox potential limits its potential applications. The use of photocatalytic materials offers a solution to this problem by converting absorbed visible light into electrons to facilitate enzyme catalysis. Herein, MIL-53(Fe) and NH2-MIL-53(Fe) serve as both light absorbers and enzyme immobilization carriers, and laccase is employed for solar-driven chemical conversion. Electron spin resonance spectroscopy results confirm that visible light irradiation causes rapid transfer of photogenerated electrons from MOF excitation to T1 Cu(II) of laccase, significantly increasing the degradation rate constant of tetracycline (TC) from 0.0062 to 0.0127 min-1. Conversely, there is only minimal or no electron transfer between MOF and laccase in the physical mixture state. Theoretical calculations demonstrate that the immobilization of laccase\'s active site and its covalent binding to the metal-organic framework surface augment the coupled system\'s activity, reducing the active site accessible from 27.8 to 18.1 Å. The constructed photo-enzyme coupled system successfully combines enzyme catalysis\' selectivity with photocatalysis\'s high reactivity, providing a promising solution for solar energy use.
摘要:
漆酶能够催化大量的反应,但其低氧化还原电位限制了其潜在的应用。光催化材料的使用通过将吸收的可见光转化为电子以促进酶催化而提供了该问题的解决方案。在这里,MIL-53(Fe)和NH2-MIL-53(Fe)作为光吸收剂和酶固定化载体,漆酶用于太阳能驱动的化学转化。电子自旋共振光谱结果证实,可见光照射导致光生电子从MOF激发快速转移到漆酶的T1Cu(II),将四环素(TC)的降解速率常数从0.0062显著提高到0.0127min-1。相反,在物理混合物状态下,MOF和漆酶之间只有最小或没有电子转移。理论计算表明,漆酶活性位点的固定及其与金属-有机骨架表面的共价结合增加了偶联系统的活性,将活动站点的可访问性从27.8减少到18.1。构建的光酶耦合系统成功地将酶催化的选择性与光催化的高反应性结合在一起,为太阳能使用提供了一个有前途的解决方案。