Sensitive electrochemical electrodes for hydrogen peroxide (H2O2) detection were developed using gold nanoclusters (NCs) to modify phosphorus incorporated tetrahedral amorphous carbon films (ta-C.P/Au) Au oxide coveted Au NCs were electrodeposited on ta-C P stir faces. and the size of Au/AuOx NCs ranged between 50 rim and 91 rim, depending on the deposition time. The ta-C P/Au electrodes exhibited higher electrocatalytic activity towards H2O2 oxidation compared to ta-C:P electrodes This is due to the three-dimensional island structure of Au/AuOx NCs, which accelerates electron exchange between ta-C.P and H2O2 in phosphate buffered solution We also found that ta-C: P/Au electrodes with Au/AuOx NCs of a smaller size and moderate coverage exhibited larger current response to H2O2 oxidation The results obtained from amperometric response curves indicated that the use of Au/AuOx NCs as microelectrodes directly favored H2O2 oxidation through hemispherical diffusion. The linear detection range of H2O2 at the non-enzymatic ta-C:P/Au electrodes was identified to be between 0.2 mu M anti 1 mM with a detection limit of 80 nM under optimized conditions These ta-C: P/Au electrodes have potential applications in H2O2 sensing due to their high sensitivity. fast response anti long-term stability. (C) 2009 Elsevier Ltd All rights reserved