Fabrication and Characterization of Macroporous Gold Hybrid Sensing Electrodes With Electroplated Platinum Nanoparticles

In this study, highly roughened macroporous Au-/Pt nanoparticles hybrid electrodes (porous Au-/nPts) were investigated. The macroporous Au was prepared by the templating and dealloying methods based on the sol-gel process. Pt nanoparticles were then electroplated onto the surface of the macroporous Au electrode under various charge conditions to achieve a high density of metal nanoparticles. The morphologies and compositions of the fabricated electrodes were then characterized using field-emission SEM and energy dispersive X-ray spectroscopy, respectively. The electrochemical responses of the as-synthesized porous Au-/nPts were tested in 1 M sulfuric acid and phosphate-buffered saline (PBS, pH 7.4) with different amounts of hydrogen peroxide. The porous Au-/nPts hybrid electrode fabricated at an electroplating charge of 70 mC exhibited the best performance characteristics, such as an ultrahigh roughness factor of 1522 (mean values), linear range of 0.01-3 mM, sensitivity of 381.8 μA·cm^-2·mM^-1, and detection limit of hydrogen peroxide of 10 μM.