Functionalization of Electrospun Poly(Acrylonitrile-co-Styrene/Pyrrole) Copolymer Nanofibers for Using as a High-performance Carrier for Laccase Immobilization
Functionalization of Electrospun Poly(Acrylonitrile-co-Styrene/Pyrrole) Copolymer Nanofibers for Using as a High-performance Carrier for Laccase Immobilization
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DOI：
10.1007/s12221-019-9290-4
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发表时间：
2019-11-01
影响因子：
2.5
通讯作者：
Elzain, Ahmed A.
中科院分区：
文献类型：
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作者：
El-Aassar, M. R.;Shibraen, Mahmoud H. M. A.;Elzain, Ahmed A.
将酶固定到纳米材料上是克服游离酶应用的困难的策略，其中固定化过程提供优异的可重复使用性和对温度和pH的操作稳定性，以及用于催化反应的高表面积。本文采用静电纺丝技术成功地制备了丙烯腈-苯乙烯/吡咯共聚物（poly（AN-co-ST/ Py））纳米纤维。将变色栓菌漆酶固定在功能化聚（AN-co-ST/Py）纳米纤维上，通过物理吸附和多点共价连接的方法将聚乙烯二胺（PEI）共价连接到聚合物表面的功能基团上。由于固定化漆酶的相对活性取决于偶联到聚合物纳米纤维上的PEI的量，因此应用通过铜离子络合物形成的比色测定来估计工艺产率。在此基础上，研究了PEI的浓度、时间、pH值和温度等因素对PEI偶联过程的影响，以及它们对纳米纤维形貌的影响。此外，热稳定性和pH稳定性，储存稳定性和可重复使用性进行了评价和比较。固定化酶的最适反应温度为70 ℃，最适pH为6.0。扫描电子显微镜（SEM）图像显示，PEI改性后的纳米纤维保持了其纳米纤维结构和均匀的形貌，平均直径约为559.2 nm。在35天内，固定化过程将活性损失从59%降低到29%，而在50 ° C下热孵育2小时导致游离酶和固定化酶的活性损失分别为65%和30%。因此，在这项工作中提出的制备的共聚物纳米纤维显示出应用于酶固定化的前景。
Enzyme immobilization onto nanomaterials is a strategy to overcome the difficulties of the free enzymes applications where the immobilization process affords excellent reusability and operational stability against temperature and pH, and high surface area for the catalytic reaction. In this work, poly(Acrylonitrile-co-Styrene/Pyrrole), (poly(AN-co-ST/ Py)), copolymer nanofibers were successfully fabricated using the electrospinning technique. Laccase enzyme from Trametes versicolor was immobilized onto functionalized poly(AN-co-ST/Py) nanofibers by covalent attachment using polyethylenediamine (PEI) via physical adsorption and multipoint covalent attachment to the functional groups onto the polymeric surface. Since the relative activity of the immobilized Laccase depends on the amount of the coupled PEI onto the polymeric nanofibers, a colorimetric assay via copper ions complex formation was applied for the estimation of the process yield. Accordingly, the various factors affecting the PEI coupling process such as concentration, time, pH and temperature were investigated; Besides their influence on the morphology of the resultant nanofibers. Furthermore, thermal and pH stability, storage stability, and reusability were evaluated and compared. The optimum reaction temperature and pH for the immobilized enzyme were 70 degrees C and 6.0, respectively. The scanning electron microscopy (SEM) images showed that the modified nanofibers with PEI have kept its nanofibers structure and uniform morphology with an average diameter of approximately 559.2 nm. Within 35 days, the immobilization process reduces the activity loss from 59 % to 29 %, while thermal incubation at 50 degrees C for 2 hrs causes activity loss for the free and immobilized enzymes by 65 % and 30 % respectively. Therefore, the prepared copolymer nanofibers proposed in this work showed promising potential for applications to enzyme immobilization.