In this work, a novel type of functionalized magnetic graphene oxide (MGO) nano-sheets which have the ability to capture His-tagged CotA laccase was synthesized. Nα,Nα-Bis(carboxymethyl)-l-lysine hydrate (NTA-NH₂) was attached on MGO then chelated with Ni²⁺ and Cu²⁺ separately. The Cu²⁺-chelated MGO (MGO-NTA-Cu²⁺) exhibited the highest adsorption capacity of 177 mg/g-support when compared with both MGO and Ni²⁺-chelated MGO (MGO-NTA-Ni²⁺) which exhibited an adsorption capacity of 49.9 and 145 mg/g-support, respectively. CotA laccase immobilized on MGO-NTA-Cu²⁺ nano-sheets showed the highest activity recovery when compared with that immobilized on MGO-NTA-Ni²⁺ nano-sheets. The catalytic properties of MGO-NTA-Cu-CotA laccase were significantly improved in comparison with those of the free laccase. MGO-NTA-Cu-CotA laccase showed efficient decolorization for Congo Red (CR), and the decolorization rate reached 100% after 5 h reaction at 60 °C and pH 8. Furthermore, MGO-NTA-Cu-CotA laccase retained 89.4% of its initial activity after 10 consecutive cycles. Together these results indicated that the Cu²⁺ chelated MGO nano-sheets are promising support for efficient CotA laccase immobilization for environmental and industrial applications under high temperature and alkaline condition.

在这项工作中，合成了一种新型的具有捕获His标记的CotA漆酶能力的功能化磁性氧化石墨烯（MGO）纳米片。将Nα，Nα-双（羧甲基）-1-赖氨酸水合物（NTA-NH ₂）附着在MGO上，然后分别与Ni ²⁺和Cu ²⁺螯合。与MGO和Ni ²⁺螯合的MGO（MGO-NTA-Ni ²⁺）相比，Cu ²⁺螯合的MGO（MGO-NTA-Cu ²⁺）表现出最高的吸附容量177 mg / g-载体。载体的吸附容量分别为49.9和145 mg / g。CotA漆酶固定在MGO-NTA-Cu ^2+上与固定在MGO-NTA-Ni ²⁺纳米片上的纳米片相比，纳米片表现出最高的活性恢复。与游离漆酶相比，MGO-NTA-Cu-CotA漆酶的催化性能显着提高。MGO-NTA-Cu-CotA漆酶对刚果红（CR）表现出有效的脱色，在60°C和pH 8下反应5小时后，脱色率达到100％。此外，MGO-NTA-Cu-CotA漆酶保留89.4％。连续10个周期后其初始活动的变化。这些结果共同表明，Cu ²⁺螯合的MGO纳米片有望在高温和碱性条件下有效地将CotA漆酶固定化，用于环境和工业应用。