Electrochemical determination of hydrogen peroxide (h2o2) at glassy carbon electrode modified with a palladium-gold co-deposite nanoparticles

Abstract

Electrochemical methods using modified electrodes have been proved to be an inexpensive and sensitive method for analysis of wide range of analytes. In this study, a sensitive sensor for the determination of hydrogen peroxide was fabricated based on glassy carbon electrode modified with Pd-Au co-deposite nanoparticles. The modified electrode showed enhanced response to hydrogen peroxide as compared to Pd nanoparticles, Au nanoparticles modified and bare glassy carbon electrodes. Among eleven mixed Pd:Au mole ratio studied (0:1), (0.1:0.9), (0.2:0.8), (0.3:0.7), (0.4:0.6), (0.5:0.5), (0.6:0.4), (0.7:0.3), (0.8:0.2), (0.9:0.1) ( 1:0); the 0.8:0.2 showed the highest response for signal for electro reduction of H2O2. The optimization of the experimental conditions such as deposition potential and deposition time of the co-deposit, pH for electroanalysis of H2O2 and reduction potential for H2O2 at modified electrode for amperometric determination was studied. The selected co-deposit demonstrated a large dynamic concentration range (5 – 170 × 10-6 mol/L) with a limit of detection of 3.8 × 10-7 mol/L under the optimized conditions. The fabricated nanoparticles were applied for analysis of H2O2 in mouth wash. The selected Pd-Au co-deposite was able to detect low concentration of hydrogen peroxide that was not possible to detect by Pd nanoparticles and Au nanoparticles modified glassy carbon electrode.