Ben-Amor S., Devin A., Rigoulet M., Sojic N., Arbault S.,
Electroanalysis 2013, 25, 656-663.
Hydrogen peroxide is a major bio-active molecule produced by mitochondria during aerobic metabolism. In order to monitor that production, platinized ultramicroelectrodes with high surface-area were used. Their sensitivity was significantly improved following an oxygen plasma treatment. Cyclic voltammetry and chrono-amperometry analyses of ferricyanide reduction and hydrogen peroxide oxidation showed that ultramicroelectrodes’ capacitive current was decreased 3-fold, while faradic currents remained constant. Then, plasma-treated ultramicroelectrodes allowed the chrono-amperometric detection of 100 nM H2O2 injections. This eventually enabled monitoring mitochondria release of H2O2 following injection of substrates and a respiratory inhibitor; a flux of few hundreds picomoles H2O2/mg protein/min was detected.