Immobilization of formate dehydrogenase on polyethylenimine-grafted graphene oxide with kinetics and stability study

Graphene oxide-based nanomaterials are promising for enzyme immobilization due to the possibilities of functionalizing surface. Polyethylenimine-grafted graphene oxide was constructed as a novel scaffold for immobilization of formate dehydrogenase. Compared with free formate dehydrogenase and graphene oxide adsorbed formate dehydrogenase, thermostability, storage stability, and reusability of polyethylenimine-grafted graphene oxide-formate dehydrogenase were enhanced. Typically, polyethylenimine-grafted graphene oxide-formate dehydrogenase remained 47.4% activity after eight times' repeat reaction. The immobilized capacity of the polyethylenimine-grafted graphene oxide was 2.4-folds of that of graphene oxide. Morphological and functional analysis of polyethylenimine-grafted graphene oxide-formate dehydrogenase was performed and the assembling mechanism based on multi-level interactions was studied. Consequently, this practical and facile strategy will likely find applications in biosynthesis, biosensing, and biomedical engineering.