Amperometric sensing of hydrogen peroxide via highly roughened macroporous Gold-/Platinum nanoparticles electrode

A macroporous Au electrode with a very rough surface arising from electroplated Pt nanoparticles (macroporous Au-/nPts) was newly developed and characterized for its suitability for hydrogen peroxide (H(2)O(2)) sensing applications. The surface morphology and composition of the macroporous Au-/nPts were measured by the use of scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. Then, the surface roughness and electro-catalytic characteristics were analyzed through the electrochemical analysis method. The porosity and window-pore size of the macroporous Au electrode were approximately 50% and 100-300 nm, respectively. The sizes of the Pt nanoparticles ranged from 5 nm to 10 nm. The roughness factors (RFs) of macroporous Au and Au-/nPts electrodes were measured and calculated by the use of cyclic voltammograms in 1 M sulfuric acid, and found to be 88.6 and 488, respectively. The fabricated macroporous Au and macroporous Au-/nPts electrodes were also characterized and compared in a 0.1 M phosphate buffer saline (PBS, pH 7.4) solution with various H(2)O(2) concentrations. The macroporous Au-/nPts electrode showed a very much higher sensitivity of 264 mu A mM(-1) cm(-2) to H(2)O(2) compared with the macroporous Au electrode (110 mu A mM(-1) cm(-2)). Furthermore it was not affected by interfering species like ascorbic acid (AA) and acetaminophen (AP). Also, the macroporous Au-/nPts exhibited an extremely low working potential of 0.1 V, detection limit of 50 mu M, and fast response time within 10-20 s. (C) 2010 Elsevier B. V. All rights reserved.