Amperometric sensing of hydrogen peroxide using glassy carbon electrode modified with rhodium

Following our previous studies on the catalytic activity of electrochemically deposited on glassy carbon Rh electrocatalyst towards the reduction of hydrogen peroxide (H2O2), the electrochemical behaviour of the modified electrode was studied by means of cyclic voltammetry and chronoamperometry at pH-values from 5.0 to 9.0. The modified electrode exhibited a rapid, sensitive and reproducible response for the quantitative determination of H2O2 at low applied potential. Amperometry carried out at constant potential of 0 V (vs. Ag/AgCl, 3M KCl) at pH 6.0 (25 oC) gave the following operational parameters: detection limit of 4 μM, linear dynamic range 0.01 – 5.5 mM and electrode sensitivity of 377 μA mM−1 cm−2 .