School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian, 116029, P.R. China.
Dalton Trans. 2021 Nov 2;50(42):15198-15209. doi: 10.1039/d1dt02644e.
A new polyoxometalate (POM)-based organic-inorganic hybrid Cu-coordination polymer, namely {((Cu(bipy))(-PhPO)Cu(bipy))H(PCuWO)·3HO} (denoted as compound 1, bipy = 2,2'-bipyridine, PhPO = phenylphosphonate), was self-assembled hydrothermally. Single-crystal X-ray diffraction (SC-XRD) analysis shows that two unique types of 1D chains are present in compound 1, Cu(II)-organophosphine and organonitrogen complex cation ([((Cu(bipy))(-PhPO)Cu(bipy))]) chains and Cu-monosubstituted Keggin-type polyoxoanion ([PCuWO]) chains, forming a hetero-POM. Crystalline compound 1 as a new enzyme immobilization support exhibited a high horseradish peroxidase (HRP) loading capacity (268 mg g). The powder X-ray diffraction (PXRD), FTIR, zeta potential, confocal laser scanning microscopy (CLSM) and circular dichroism (CD) results show that HRP is only immobilized on the surface of compound 1 through simple physical adsorption without a secondary structure change. This POM-immobilized enzyme (HRP/1) was first used for degradation of pollutants in wastewater, and it showed a high degradation efficiency and TOC removal efficiency for phenol, 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) within 30 min reaction time. Moreover, HRP/1 exhibited better operational and storage stabilities and reusability compared with free HRP. This work suggests that POMs can be used as new supports for enzyme immobilization and POM-immobilized enzymes may be used as a new kind of biocatalyst for degradation of phenolic pollutants.
一种新的多金属氧酸盐（POM）基有机-无机杂化 Cu 配位聚合物，即{((Cu(bipy))(-PhPO)Cu(bipy))H(PCuWO)·3HO}（表示为化合物 1，bipy = 2,2'-联吡啶，PhPO = 苯膦酸），是通过水热自组装合成的。单晶 X 射线衍射（SC-XRD）分析表明，化合物 1 中存在两种独特的 1D 链，Cu(II)-有机膦和有机氮配合物阳离子([((Cu(bipy))(-PhPO)Cu(bipy))])链和 Cu-单取代 Keggin 型多氧阴离子([PCuWO])链，形成杂多阴离子。结晶化合物 1 作为一种新的酶固定化载体，具有较高的辣根过氧化物酶（HRP）负载量（268mg g）。粉末 X 射线衍射（PXRD）、傅里叶变换红外光谱（FTIR）、ζ 电位、共聚焦激光扫描显微镜（CLSM）和圆二色性（CD）结果表明，HRP 仅通过简单的物理吸附固定在化合物 1 的表面，而没有发生二级结构变化。这种 POM 固定化酶（HRP/1）首次用于废水污染物的降解，在 30min 反应时间内对苯酚、4-氯苯酚（4-CP）和 2,4-二氯苯酚（2,4-DCP）表现出较高的降解效率和 TOC 去除效率。此外，与游离 HRP 相比，HRP/1 表现出更好的操作稳定性、储存稳定性和可重复使用性。这项工作表明，POM 可用作酶固定化的新型载体，POM 固定化酶可用作降解酚类污染物的新型生物催化剂。
