Due to its environmental friendliness and biodegradable ability, the enzymatic decolorization of azo dyes is the best option. However, the free enzyme suffers from various limitations, including poor stability, no repeatable use, and a high expense, which is the key drawback for its practical use. In this analysis, the laccase enzyme was immobilized in mesoporous silica coated magnetic multiwalled carbon nanotubes (Fe₃O₄-MWCNTs@SiO₂) by a glutaraldehyde cross-linker to create an easily separable and stable enzyme. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the as-synthesized Fe₃O₄-MWCNTs@SiO₂. Laccase immobilized in Fe₃O₄-MWCNTs@SiO₂ showed a good improvement in temperature, pH, and storage stability. Moreover, the operational stability of the biocatalyst was improved, retaining 87% of its original activity even after 10 cycles of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) oxidation. The biocatalysts were applied for the decolorization of selected azo dyes without a mediator, and up to 99% of Eriochrome Black T (EBT), 98% of Acid Red 88 (AR 88), and 66% of Reactive Black 5 (RB5) were decolorized. Based on these properties, the biocatalysts can be potentially utilized in various environmental and industrial applications.

中文翻译：

---

通过共价固定在介孔二氧化硅涂层磁性多壁碳纳米管上的漆酶活性提高，用于合成染料的变色

由于其对环境友好和可生物降解的能力，偶氮染料的酶法脱色是最佳选择。但是，游离酶具有各种局限性，包括稳定性差，不能重复使用和费用高，这是其实际应用的主要缺点。在该分析中，漆酶通过戊二醛交联剂固定在介孔二氧化硅涂层的磁性多壁碳纳米管（Fe ₃ O ₄ -MWCNTs @ SiO ₂）中，以创建易于分离和稳定的酶。使用傅立叶变换红外（FTIR）光谱，扫描电子显微镜（SEM）和能量色散X射线光谱（EDX）表征了合成后的Fe ₃ O ₄ -MWCNTs @ SiO₂。固定在Fe ₃ O ₄ -MWCNTs @ SiO _2中的漆酶在温度，pH和储存稳定性方面都有很好的改善。此外，该生物催化剂的操作稳定性得到了改善，即使经过10个2，2'-叠氮基双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）氧化反应，仍可保持其原始活性的87％。该生物催化剂被用于在没有介体的情况下对选定的偶氮染料进行脱色，并且高达99％的铬铁黑T（EBT），98％的酸性红88（AR 88）和66％的活性黑5（RB5）脱色。基于这些性质，生物催化剂可以潜在地用于各种环境和工业应用中。