A novel electrochemical sensor for formaldehyde based on palladium nanowire arrays electrode in alkaline media

A novel electrochemical sensor for the detection of formaldehyde based on palladium (Pd) nanowire (NW) arrays was developed. The Pd NW arrays were obtained via the direct electrodeposition of Pd on a glassy carbon electrode within the pores of an anodized aluminum oxide membrane. The electrocatalytic activity of the Pd NW arrays electrode for formaldehyde detection in alkaline media was then investigated via a series of electrochemical measurements; the results show the very high catalytic activity of the electrode. The formaldehyde oxidation on the Pd NW arrays electrode at +0.03 V, which is more negative than that in previous report. The experimental data further reveal that the electrooxidation of formaldehyde inhibits the formation of the poisonous intermediate, carbon monoxide. The proposed sensor has high sensitivity and fast response to formaldehyde, and the oxidation current has a linear relationship with the formaldehyde concentration in the 2 μM to 1 mM range (R = 0.9982). The detection limit was 0.5 μM (S/N = 3). The sensor has high sensitivity and good selectivity.