Immobilization of glucoamylase on triazine-functionalized Fe3O4/graphene oxide nanocomposite: Improved stability and reusability.

Immobilization of an enzyme can enhance its catalytic activity, depending on the properties of the enzyme and the matrix. Graphene oxide is a nontoxic material and selective modulator for enzyme activity and is also a thermostable molecule that is important in large-scale nanostructure sheet applications. Herein, we have successfully developed a strategy for preparing a nanocomposite for enzyme immobilization model with high loading capacity. Nanostructures of hybrid graphene oxide-Fe3O4-cyanuric chloride (GO/MNP-CC) have adjustable surface chemistry that is an excellent candidate for covalent immobilization of enzymes. The morphology, structure and properties of GO/MNP-CC nanocomposite were investigated through different analytical tools. Glucoamylase, an important enzyme in industrial food products, was immobilized on GO/MNP-CC and exhibited excellent catalytic activity at pH 6.5 and 60°C. The results of this study indicated that the catalytic activity, reusability and stability of immobilized enzyme have been obviously improved compared to the free enzyme. The apparent Km and νmax for free and immobilized glucoamylase were also determined. These properties make them a good candidate to improve the practicality and further the development of the capacity enzyme attachment. Thus, the synthesized matrix has the potential for practical applications in other and binary enzyme immobilization and would have a wide prospect for their applications in bio-industry and biosensing.