A green approach for the reduction of graphene oxide nanosheets using non-aromatic amino acids

A simple and green chemistry approach for the preparation of reduced graphene oxide nanosheets through the reduction of graphene oxide (GO) using non-aromatic and thiol-free amino acids as the reductant was successfully demonstrated. l-Aspartic acid and valine amino acids were used as models to prove that the reduction method is generic to other amino acids. The significance of the proposed method is that it eliminates the use of toxic and harmful chemicals to humans and the environment, which makes it compatible for the large-scale production of graphene. Reduced GO nanosheets showed good stability in aqueous dispersions due to the strong electrostatic repulsion on the graphene surface. Structural studies confirmed the deoxygenation of GO from the loss of hydroxyl, carbonyl and epoxy groups, and preparation of graphene sheets between 20 and 70 nm suitable for broad biomedical applications.