Sensitive electrochemical detection of nereistoxin by reductive desorption from Au(111) and Au(100)

Sensitive electrochemical detection of nereistoxin (NEX), a widely used insecticide, by reductive desorption is studied. NEX is adsorbed onto a gold single-crystal electrode via its disulfide group to form a self-assembled monolayer (SAM), which shows a reductive desorption peak in alkaline solution. The detection limit depended on the modification time and the crystallographic orientation of Au. When a Au(111) electrode was used as a substrate, the limit of detection was 10 nM. This limit was decreased to 1 nM when a Au(100) electrode was used. The NEX-SAM on a Au(111) and Au(100) electrode also showed a characteristic reductive wave, which allowed NEX to be distinguished from other similar compounds such as aminoethanthiol, N-dimethylaminoethanthiol, and aminohexanethiol. (C) The Electrochemical Society of Japan, All rights reserved.