Potentiometric determination of hydrogen peroxide at MnO2-doped carbon paste electrode

A novel hydrogen peroxide (H2O2) potentiometric sensor, made with a MnO2-do ped carbon paste electrode (CPE), is reported. Under optimum conditions, th e electrode gives a Nernstian response for H2O2 in the concentration range 3.00 x 10 (- 7) -3.63 x 10 (- 4) mol/l, with a slope of 21-19.4 mV/pH(2)O(2 ) and a detection limit of 1.2 x 10 (- 7)mol/l H2O2. In addition, this sens or offers some analytical characteristics such as sensitivity, good reprodu cibility and a simple preparation procedure. The effects of both the compon ents of the electrode and other conditions on the potential response of the sensor, as well as the possible response mechanism, are discussed. (C) 200 0 Elsevier Science B.V. All rights reserved.