Polypyrrole-based electronic noses for environmental and industrial analysis

The use of polypyrrole (PPy)-based electronic noses (ENs) for environmental and industrial analysis has gained considerable momentum in the past decade. Toxic and non-toxic substances, such as ammonia, nitrogen oxides, carbon monoxide, sulphur dioxide, hydrogen sulphide, methane, oxygen, hydrogen, alcohols, phenol, benzene and water vapours have been successfully determined by PPy-based ENs in materials ranging from water and beverages to waste waters and sewage effluents. This article reviews the various research efforts that have been carried out over the past decade on the development of PPy-based ENs for environmental and industrial analysis. It also provides an overview on future prospects and development of ENs for broader applications in this area. (c) 2004 Elsevier B.V. All rights reserved.