N and B Co-Doped Graphene: A Strong Candidate to Replace Natural Peroxidase in Sensitive and Selective Bioassays.

It describes a new carbon-based peroxidase mimic, N and B co-doped reduced graphene oxide (NB-rGO), which show unprecedentedly high peroxidase-like activity without oxidase-like activity, and that has up to 1000 times higher catalytic efficiency than does undoped rGO. The high catalytic activity of NB-rGO is explained by density functional theory (DFT) by calculating Gibbs free energy change during the peroxide-decomposition reaction. Acetylcholine and C-reactive protein are successfully quantified with high sensitivity and selectivity, which were comparable to or better than those obtained using natural peroxidase. Furthermore, NB-rGO which doesn't have oxidase-like activity is proved to have higher sensitivity toward acetylcholine than Pt nanoparticles having oxidase-like activity. This work will facilitate studies on development, theoretical analysis for rational design, and bioassay applications of enzyme mimics based on nanomaterials.