Electrochemical detection of ammonia using a thin ionic liquid film as the electrolyte

Abstract

In this paper, an electrochemical sensor platform is presented in which a thin film of an ionic liquid is used as the electrolyte, in combination with a planar microfabricated electrode configuration. It is demonstrated that this ionic liquid film-based sensor can detect ammonia (NH3) at levels as low as 1 ppm in ambient conditions. Moreover, both amperometry and cyclic voltammetry are successfully applied to detect NH3. However, amperometric measurements are hampered by a decreasing sensitivity ('fouling') during NH3 exposure. No fouling is observed while using cyclic voltammetry for NH3 detection, which therefore seems to be the most promising method for practical application.