Application of the immobilized enzyme on magnetic graphene oxide nano-carrier as a versatile bi-functional tool for efficient removal of dye from water

Herein, we report bi-functional applications of a novel immobilized enzyme on the modified magnetic graphene oxide (GO) for effective removal of dyes from water. The amine functionalized GO nano-carrier was covalently attached to a model enzyme (PersiManXyn1). The enzyme assays showed that the specific activities of the free and immobilized enzyme were 856.05 and 1141.1 µmolmin⁻¹mg⁻¹, respectively. While the free enzyme showed only 5% of its maximum activity, the immobilized PersiManXyn1 preserved more than 35% of its activity, at 90 °C. After four weeks storage, the free enzyme has been deactivated, but the immobilized enzyme retained 54% of its initial activity. The immobilized PersiManXyn1 was proficiently applied for dye removal from water using two strategies. While only pristine nano-carrier and free enzyme showed no considerable catalytic ability, the immobilized PersiManXyn1 could catalytically reduce the concentrated dye solutions within 150 s with superior reusability (94% dye removal after 15^th cycle). Proficient treatment of a real textile effluent by the immobilized PersiManXyn1 approved its practical applications in the water remediation.