Sensitive nonenzymatic detection of hydrogen peroxide at nitrogen-doped graphene supported-CoFe nanoparticles.

In this work, a new enzymeless sensor for hydrogen peroxide (H2O2) was constructed by supporting CoFe nanoparticles on the nitrogen-doped graphene (CoFe/NGR). In this preparation, the graphene oxide (GO) is first used as substrate for the growth of CoFe layered double hydroxides (CoFe LDHs) through hydrothermal reaction. Then, the pyrolysis of CoFe LDHs/GO under NH3 produces CoFe/NGR. By supporting CoFe nanoparticles on NGR support, the electrocatalytic performance of CoFe is dramatically improved because of high electric conductivity of NGR. Consequently, the combination of CoFe and NGR allows the nonenzymatic detection of H2O2. Compared with the unsupported CoFe nanoparticles, the CoFe/NGR displays high electrocatalytic activity towards H2O2, enabling a high sensitivity of 435.7 μA mM-1 cm-2 and low detection limit of 0.28 μM towards the reduction of H2O2. Especially, the attractive feature of low cost and outstanding analytical performance of CoFe/NGR suggest it great potential in electrochemical sensor and biosensor fabrication.