The electrochemistry of hydrogen peroxide on evaporated gold/palladium composite electrodes. Manufacture and electrochemical characterization

Abstract

A thin-film composite metal electrode is described for the amperometric measurement of hydrogen peroxide. By thermally evaporating a 27pm layer of gold/palladium through a copper mask onto a plastic substrate a number of chemically equivalent sensing elements can be prepared. On these electrodes, hydrogen peroxide can be oxidized at a voltage of 0.4V (SCE). A model for the oxidation of peroxide at these electrodes is described based upon revers.ible binding of hydrogen peroxide to electrochemically generated palladium oxide sites.

Comparisons of platinum, gold, palladium and glassy carbon as electrode materials in the design of biosensors for glutamate

“…1), the voltammetric behaviour of H 2 O 2 fell into two classes. At Pt and Pd, H 2 O 2 oxidation occurred at relatively low applied potentials, consistent with electrocatalysis by surface oxides for both metals (Johnston et al, 1995;Hall et al, 1998); Au and GC displayed significantly higher overpotentials. In addition, there was a cathodic arm in the background-subtracted H 2 O 2 CVs for Pt and Pd, absent for both Au and GC, which is due to the reduction of H 2 O 2 (O'Connell et al, 1998).…”

“…1). The behaviour of Pt and Pd were similar in having pronounced cathodic arms associated with the reduction of oxides on the surface of both metals (Johnston et al, 1995;Hall et al, 1998), although the current density scale was a factor of five smaller for Pd. Au displayed a classically capacitance shape up to a late upswing, presumably associated with Au dissolution (Gerlache et al, 1997).…”

A study of the electrochemical oxidation of hydrogen peroxide on a platinum rotating disk electrode in the presence of calcium ions using Michaelis–Menten kinetics and binding isotherm analysis

“…Applying Eq. (17) may help to explore the influence of Ca 2+ ions on the stability of the surface complex sites given in reaction (1) and determine the number of H 2 O 2 molecules bound to the active sites. It should be noted also; that the smooth curves shown in Fig.…”

“…Consequently, the data presented in Fig. 6 were further analyzed by applying non-linear least-square fitting to evaluate the stability constant for surface complex sites described by reaction (1).…”

“…Hydrogen peroxide (H 2 O 2 ) has received a great deal of attention for industrial, clinical, biotechnology and environmental analysis due to its characteristic nature as a universal oxidant and for its involvement in many biological reactions as a product of several enzymatic reactions [1][2][3][4][5][6]. Biosensors were constructed and used extensively as they combine the specificity of the biological recognition processes with the electroanalytical signal [7].…”