Sensitive determination of hydrogen peroxide based on a novel nonenzymatic electrochemical sensor: silver nanoparticles decorated on nanodiamonds

In the present work, we report the fabrication and application of a sensitive nonenzymatic hydrogen peroxide (H2O2) sensor, using a nanocomposite, based on the nanodiamonds (NDs) decorated with silver nanoparticles (AgNPs/NDs). The AgNPs/NDs nanocomposite was prepared via a facile and efficient process. The field emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were applied for characterization of the obtained nanocomposite. The electrochemical investigations have shown that the resulting AgNPs/NDs nanocomposite modified electrode has strong electrocatalytic activity toward H2O2 reduction which is attributed to the NDs that promoted the formation, uniform distribution, and electrocatalytic activity of the AgNPs. In the optimum conditions, the linear response range of the constructed H2O2 sensor was from 0.1 to 34.0 A mu M at applied potential of -0.2 V with a detection limit of 0.01 mu M (S/N = 3). Also, the proposed sensor showed high sensitivity of 1.59 x 10(6) A mu AM(-1) and was applied to measure the concentration of H2O2 in real samples. These results indicate that the AgNPs/NDs nanocomposite with high conductivity and stability has a promising potential in electrochemical sensors development. Electroreduction of H2O2 on the AgNPs/NDs/GCE.