Effect of graphene oxide with different morphological characteristics on properties of immobilized enzyme in the covalent method
Effect of graphene oxide with different morphological characteristics on properties of immobilized enzyme in the covalent method
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DOI：
10.1007/s00449-020-02375-9
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发表时间：
2020-05
影响因子：
3.8
通讯作者：
Han Zhang;Shao‐Feng Hua;Cong-qiang Li;Lei Zhang;Yunchang Fan;P. Duan
中科院分区：
文献类型：
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作者：
Han Zhang;Shao‐Feng Hua;Cong-qiang Li;Lei Zhang;Yunchang Fan;P. Duan
虽然氧化石墨烯（GO）在固定化酶催化剂领域具有很大的潜力，但不同形态结构的氧化石墨烯对固定化酶的具体影响尚不清楚。以8000目石墨和纳米级石墨为原料，在不同反应温度下制备了氧化石墨烯，并用交联法作为载体固定化α -淀粉酶。通过原子力显微镜、傅里叶变换红外光谱、x射线光电子能谱、拉曼光谱和紫外可见光谱对氧化石墨烯的性质进行了表征。考察了交联剂用量、交联时间、最适温度/pH、热/pH/贮存稳定性、可重复使用性和固定化酶的动力学参数。结果表明：α -淀粉酶在GOs上的负载为162.3 ~ 274.2 mg g−1；重复使用实验表明，固定化α -淀粉酶在7个反应周期后仍能保持较高的活性。与游离酶相比，固定化酶的贮藏稳定性得到了提高，在4℃条件下贮存20 d后，固定化酶的活性仍保持在初始活性的70%以上。
Although graphene oxide (GO) has great potential in the field of immobilized enzyme catalysts, the detailed effects of GO with different morphological structures on immobilized enzyme are not well understood. GOs were prepared from 8000 mesh and nanoscale graphite at different reaction temperatures, and used as carriers to immobilize alpha-amylase by cross-linking method. The properties of GOs were characterized through Atomic force microscope, Fourier-transformed infrared, X-ray photoelectron spectroscopy, Raman and UV–Vis. Furthermore, the dosage of cross-linking agent, cross-linking time, optimum temperature/pH, thermal/pH/storage stability, reusability and kinetic parameters of immobilized enzymes were investigated. The results showed that the loading of alpha-amylase on GOs was 162.3–274.2 mg g−1. The reusability experiments revealed high activity maintenance of immobilized alpha-amylase even after seven reaction cycles. Moreover, the storage stability of immobilized enzyme improved via immobilization in comparison with free one and it maintained over 70% of their initial activity after 20 days storage at 4 °C.