Highly activated screen-printed carbon electrodes by electrochemical treatment with hydrogen peroxide

An easy effective method for the activation of commercial screen-printed carbon electrodes (SPCEs) using H2O2 is presented to enhance sensing performances of carbon ink. Electrochemical activation consists of 25 repetitive voltammetric cycles at 10 mV s(-1) using 10 mM H2O2 in phosphate buffer (pH 7). This treatment allowed us to reach a sensitivity of 0.24 +/- 0.01 mu A mu M-1 cm(-2) for the electroanalysis of H2O2, which is 140-fold higher than that of untreated SPCEs and 6-fold more than screen-printed platinum electrodes (SPPtEs). Electrode surface properties were characterized by SEM, EIS and XPS. The results revealed atomic level changes at the electrode surface, with the introduction of new carbon-oxygen groups being responsible for improved electro-transfer properties and sensitivity. Our method was compared with other previously described ones. The methodology is promising for the activation of commercial carbon inks-based electrodes for sensor applications.