Development and Evaluation of ZnO-Fe₂O₃ Based Nanocomposite Sensors for Butanol Detection

Olfactory sensing of specific volatile organic compounds released by bacterial pathogens is one of the unique ways for determining microbial contamination in packaged food products. This study reports the development and evaluation of zinc oxide-iron oxide (ZnO-Fe₂O₃) nanocomposite sensors to detect low concentrations of butanol, one of the VOCs specific to Salmonella contamination in packaged beef, at low operating temperature (100 °C). The ZnO-Fe₂O₃ sensor was developed using modified sol–gelsol method on an interdigitated alumina substrate. The sensor thin film characterization confirmed a uniform layer of ZnO-Fe₂O₃ thin film formation with ZnO nanorods of 100 nm height. Also, ZnO-Fe₂O₃ nanocomposite sensor demonstrated repeatable responses and good sensitivity to butanol with an estimated lower detection limit of about 26 ppm at 100 °C.