Enhanced electrocatalytic reduction and highly sensitive nonenzymatic detection of hydrogen peroxide using platinum hierarchical nanoflowers

A highly sensitive nonenzymatic sensor was fabricated based on platinum hierarchical nanoflowers synthesized using a sonoelectrodeposition method. The morphology, structure and fractal properties of the nanoflowers were discussed based on image analysis. The catalytic activity and sensitivity of the nanoflowers toward the electroreduction of hydrogen peroxide were excellent without deterioration. Voltammetric and polarization measurements were used to evaluate the kinetics of hydrogen peroxide on the nanoflowers' surface under the physiological conditions. The results showed that the nanoflowers can be utilized to fabricate a hydrogen peroxide sensor. At an applied potential of 0.21 V (vs. Ag/AgCl), the current reduction of hydrogen peroxide rapidly and linearly depended on its concentration with a sensitivity of 1.39 A mol L−1 cm−2, and a limit of detection of 0.32 μmol L−1. The nanoflowers represented many advantages as a hydrogen peroxide sensor such as simple preparation method without using any specific enzyme or reagent, excellent catalytic activity, high sensitivity and selectivity, long-term stability, and antifouling property. Sensitivity and detection limit of the present sensor are better or comparable with those reported in the literature.