Electrochemical sensor for formaldehyde based on Pt-Pd nanoparticles and a Nafion-modified glassy carbon electrode

A novel electrochemical sensor for the determination of formaldehyde is introduced based on electrodepositing nanostructured platinum-palladium alloy in Nafion film-coated glassy carbon electrode. Bimetallic Pt-Pd nanoparticles are found to be uniformly dispersed in Nafion film, as confirmed by scanning electron microscopic analysis. Energy dispersed X-ray analysis is used to characterize the composition of metal present in the nanoparticle-modified electrodes. The electrocatalytical behavior of the electrode is investigated by cyclic voltammetry and linear sweep voltammetry. Experimental results show that the electrode displays a remarked electrocatalytic activity for the oxidation of formaldehyde and exhibits a linear relationship in the range of 10 mu M to 1 mM, with a detection limit of 3 mu M in acidic solution. The low detection limit, wide linear range, and high sensitivity of the sensor make it valuable for further application.