Nanoporous gold for amperometric detection of amino-containing compounds

• Nanoporous gold (NPG) thin films were prepared by dealloying of AuSi films.
• Amperometric sensing of aniline and phenylamine with prepared NPG thin films realized.
• Sensor sensitivity of NPG thin films towards aniline and phenylamine could be controlled by their porosity.
• NPG thin films showed good resistance towards electrode fouling.

Nanoporous gold thin films were prepared by electrochemical dealloying of Si out of AuxSi1−x co-deposited on Si substrate. The x values were easily controlled in the range of 0.1–0.9 by the distances between the sample position and the target positions at a constant plasma power. Structure of pores and gold ligaments could be controlled via adjusting the alloy compositions. The gold nanoporous films were applied for amperometric sensing of phenylamine (aniline) and hydroxylamine. It was found that the sensitivity of the nanoporous gold films was correlated with their porosity. Furthermore, nanoporous gold films with roughness factor of around 25 provided high sensitivity, good repeatability, relatively low detection limit and good resistance toward electrode fouling as compared to other electrodes in the literature. These achievements offer a simple method for nanoporous gold films which exhibit stable performance in environmental monitoring.