Nanoparticulate Zinc Oxide Chemoresistive Sensor for Volatile Acetic Acid Detection

Volatile organic compounds (VOCs) released by food-borne pathogens can be used as an indicator for detecting food contamination. One of our current research thrusts is to develop novel sensors that are sensitive to a speci?c compound (at room or low operating temperatures) associated with food safety. This study describes the fabrication of zinc oxide (ZnO) nanoparticulate chemoresistive sensors using sol?gel techniques (dip and spin coating) to detect acetic acid, one of the VOCs associated with packaged meat contamination, at 100°C. In addition to two types of sol?gel tech- niques, this study has also evaluated the effect of two complexing agents (diethanolamine-DEA and monoethanolamine-MEA) on ZnO nanoparticles formation and sensor sensitivities. Sensors sensitivity analysis results revealed that the ZnO sensors were sensitive to acetic acid at trace concentrations, i.e., at low ppm. The sensor sensitivity increased with increasing acetic acid concen- tration and exhibited a linear correlation coef?cient of higher than 0.83. Estimated lower detection limits for acetic acid sensing were about 30 ppm. Thus, developed ZnO nanoparticulate sensors can potentially be used in a sensor array of electronic nose systems, for packaged food contamination detection.