Carbon nanotube/Prussian blue paste electrodes: Characterization and study of key parameters for application as sensors for determination of low concentration of hydrogen peroxide

In this work carbon nanotubes paste electrodes were innovatively modified by Prussian blue and used as a sensor for H2O2 at low concentration. These electrodes were characterized by Raman spectroscopy and scanning electron microscopy to attest the modification. Influence of pH, storage conditions and numbers of cycles were studied and related to the amount of PB deposited and its behavior on H2O2 detection. The electrode modified by 500 cycles and maintained in air obtained the best H2O2 responses, with high electrochemical stability, good repeatability, reproducibility and a linear range, with limit of detection and sensitivity of 4.74 × 10−9 mol L−1 and 31.4 A cm−2/mol L−1, respectively. Interference tests were made with six different species with four of them showing less than 1% of deviation in H2O2 detection.