Characterisation of polymer nanocomposite sensors for quantification of bacterial cultures

Decomposition of food is caused by microorganisms, which produce odorous gases as a result of metabolic products. The early detection and control of these organisms provides a longer shelf life and prevents food poisoning. The identification of aerobic and anaerobic bacterial cultures in food can take up to 3 days or longer using existing laboratory techniques. Conducting polymer nanocomposite (CPC) materials are of special interest to the gas sensor industry where arrays of polymer composites may be used to detect gases and odours. These composite gas sensors operate at room temperature, which provides an advantage over thick film metal oxide gas sensors. CPC sensors are composed of conducting particles embedded into an insulating polymer matrix. The resistance changes of the sensors in the array are used to produce a pattern that corresponds to the vapour under investigation. This study presents the use of an array of CPC sensors for real time analysis and quantification of the odours given off a selection of food borne pathogens including Salmonella spp., Bacillus cereus and Vibrio parahaemolyticus.