Graphene based nanomaterials as chemical sensors for hydrogen peroxide – A comparison study of their intrinsic peroxidase catalytic behavior

In this paper we present for the first time the catalytic activity of N-doped graphene toward a peroxidase substrate oxidation in the presence of hydrogen peroxide. In addition, the activity was compared with that of metallic nanoparticles decorated-graphene, achieved either by catalytic chemical vapor deposition with induction heating (CCVD-IH) or by chemical reduction of graphene oxide (GO). From all investigated graphene-based nanomaterials, the highest activity was exhibited by N-doped graphene and gold nanoparticles supported on chemically-reduced graphene oxide. The steady-state kinetic of the two nanocomposites was carried-out in order to evaluate their peroxidase-mimetic activity. Doping the graphene surface with nitrogen atoms led to a nanomaterial with a better affinity toward hydrogen peroxide compared to the natural enzyme (horseradish peroxidase). Additionally, the systematic study of the catalytic activity for a variety of graphene-based nanomaterials offered important findings for designing new nanomaterials with peroxidase-like activity.