Graphene Flagship researchers show how graphene oxide, suspended in water, biodegrades in a reaction catalyzed by a human enzyme, with the effectiveness of the breakdown dependent on the colloidal stability of the suspension. The study should push forward the development of graphene-based biomedical applications.
As part of the interest in the health and safety aspects of graphene, risks are being investigated by researchers linked with Europe's Graphene Flagship with the safe disposal of graphene at the end of its useful life being of particular interest. The scientists examined the biodegradation of graphene oxide by an enzyme. They show that myeloperoxidase, derived from human white blood cells in the presence of a low concentration of hydrogen peroxide, can completely metabolize graphene oxide in the case of highly dispersed samples. They also found that highly aggregated suspensions of graphene oxide fail to biodegrade in the presence of myeloperoxidase, but the more stable colloids were completely broken down by the enzyme.
The researchers state that this study demonstrates the complete breakdown of graphene oxide by myeloperoxidase, and the results indicate that accidental inhalation of graphene oxide presents a manageable health risk in humans and other species. But the translation of graphene-based materials into clinically safe biomaterials for biomedical applications is also judged by biodegradability, and the study may provide a method for the environmentally safe disposal of graphene-based materials. It could also guide the development of biocompatible graphene-based carriers for the delivery of bioactive molecules.