Preparation of N-doped graphene by reduction of graphene oxide with mixed microbial system and its haemocompatibility

A steady, effective and environment friendly method of introducing nitrogen into graphene is by microbial reduction of graphene oxide with mixed microorganisms from the anode chamber of microbial fuel cells (MFC). Using this method, N-doped graphene is easily obtained under mild conditions and by simple treatment processes, with the N/C ratio reaching 8.14%. Various characterizations demonstrate that the as-prepared N-doped graphene has excellent properties and is comparable with, and in some aspects, even better than, pristine graphene (containing only elemental C) prepared by chemical methods. The N-doped graphene (mainly substitution of C in the plane of the graphene sheet) with uniform distribution of N was haemocompatible, nontoxic, and water-dispersible, all of which are desirable properties for biomaterials and attributable to a synergetic metabolic effect of mixed microorganisms.