Effect of Working Atmospheres on the Detection of Diacetyl by Resistive SnO2 Sensor

Abstract

Nanostructured metal oxide semiconductors (MOS) are considered proper candidates to develop low cost and real-time resistive sensors able to detect volatile organic compounds (VOCs), e.g., diacetyl. Small quantities of diacetyl are generally produced during the fermentation and storage of many foods and beverages, conferring a typically butter-like aroma. Since high diacetyl concentrations are undesired, its monitoring is fundamental to identify and characterize the quality of products. In this work, a tin oxide sensor (SnO2) is used to detect gaseous diacetyl. The effect of different working atmospheres (air, N2 and CO2), as well as the contemporary presence of ethanol vapors, used to reproduce the typical alcoholic fermentation environment, are evaluated. SnO2 sensor is able to detect diacetyl in all the analyzed conditions, even when an anaerobic environment is considered, showing a detection limit lower than 0.01 mg/L and response/recovery times constantly less than 50 s.

Competitive Detection of Volatile Compounds from Food Degradation by a Zinc Oxide Sensor

“…Food quality evaluation, shelf-life determination, and raw product control are important fields in which conductometric gas sensors have been applied in recent years. In these sensors, the gas detection mechanism is based on the conductance variation of a semiconducting metal oxide (MOX) layer caused by the chemical/physical adsorption of the gas molecules on the MOX surface [1]. MOX sensors have been intensively studied and used for their low production cost, reduced size, and high sensitivity to a broad range of chemicals.…”