Is graphene worth using in biofuel cells?

There is an enormous growth of interest in graphene, a two-dimensional carbon nanomaterial, exhibiting excellent conductivity, good mechanical and optical properties with an affordable cost. It was also found out that it can be integrated quite effectively with biocatalysts for fabrication of graphene-based biofuel cells (BFCs), where the biocatalysts are used for turning a chemical energy of substrates/biofuels into electricity. Like other nanomaterials, graphene can be applied for preparation of highly structured electrode interfaces, where high amount of biocatalysts can be loaded and thus the power output of a BFC can be increased. As a reflection of the fact that both graphene and BFCs are quite "hot topics" these days, the aim of this review is to cover and evaluate the current state of graphene applications in BFCs, either enzymatic or microbial, and also to answer the question whether it is indeed more favorable to use graphene instead of more common carbon nanotubes or metallic nanoparticles. (C) 2014 Elsevier Ltd. All rights reserved.