An Amperometric Hydrogen Peroxide Biosensor Based on Myoglobin Immobilized on SDS-GNPs-GR Modified Electrode

Chemically reduced graphene and gold nanoparticles composites were obtained using sodium dodecyl sulfate (SDS) as stabilizing agent and successfully dispersed fully in water to form a stable black aqueous solution. The as-prepared graphene and gold nanoparticles composites were successfully immobilized on electrode surface to construct a SDS-GNPs-GR modified electrode. The composites showed an obvious promotion of the direct electron transfer between myoglobin (Mb) and the underlying electrode. The experimental results also clarified that the adsorbed Mb retained its biological activity toward the reduction of hydrogen peroxide with high sensitivity and fast response. The biosensor possesses a linear response range of 0.45-8.1 mu M H2O2 with a correlation coefficient of 0.9989 and a detection limit of 1.2x10(-8) M based on a signal-to-noise ratio of 3.