Electrochemical Detection of Manzeb Using Reductive Desorption from Au(111) and Au(100)

Electrochemical detection of ethylenebis(dithiocarbamic acid) manganese zinc complex (Manzeb), a widely used insecticide, by reductive desorption from Au(111) and Au(100) has been studied. Dithiocarbamate groups containing adlayer were formed on gold single-crystal electrodes by immersing into a Manzeb aqueous solution. The electrochemical responses and the adsorption amounts were evaluated based on the reductive desorption of sulfur species from the gold surface in alkaline solution. The detection limit for Manzeb depended on the modification time and the crystallographic orientation of gold. The limits of detection were 500 nM and 100 nM when a Au(111) electrode and a Au(100) electrode were used, respectively. The surface-enhanced infrared absorption spectra of Manzeb on a Au thin film electrode in its monolayer state showed that Manzeb was adsorbed on the substrate via the dithiocarbamate moiety and the long axis of ethylenebis(dithiocarbamate) dianion was almost perpendicular to the surface. (c) The Electrochemical Society of Japan, All rights reserved.