Determination of hydrogen peroxide using a Prussian Blue modified macroporous gold electrode

Abstract

We describe an electrochemical sensor for hydrogen peroxide (H2O2) that is making use of Prussian Blue (PB) electrodeposited on a macroporous (mp) gold skeleton electrode. An mp-Cu film was first prepared as a template and the converted into an mp-Au film through a replacement reaction without destructing the structure. Next, a layer of PB was electrochemically deposited on the surface of the mp-Au film. The surface morphology of the electrode was characterized by scanning electron microscopy. Attenuated total reflection infrared spectroscopy and X-ray photoelectron spectroscopy were applied to confirm the structural features. The mp-PB/Au film electrode displays high electro-catalytic activity for the reduction of H2O2 at a working potential of −50 mV (vs. Ag/AgCl) and is very stable. It has a linear response to H2O2 in the 50 μM to 11.3 mM concentration range and a sensitivity of 767 μA∙mM−1 cm−2. The electrode also revealed good selectivity in the presence of electro-active species such as ascorbic acid and uric acid.