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

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. (C) 2015 The Authors. Published by Elsevier Ltd.