Pd-decorated ZnO nanoflowers as a promising gas sensor for the detection of meat spoilage

ZnO and Pd-decorated ZnO nanoflowers are synthesized by a simple wet chemical method directly on interdigitated electrodes as promising amine sensors, which can potentially indicate meat spoilage. XRD and XPS characterization show the existence of crystalline, stoichiometric ZnO along with metallic Pd in the Pd-decorated ZnO materials. SEM and TEM studies show a nanoflower morphology, with well dispersed Pd nanoparticles on the surface of the ZnO nano- “petals”. The chemiresistive gas sensing response is studied at different concentrations of methylamine (in the range of 25–400 ppm in air) and at different temperatures (25–250 °C), showing a superior response of 99.5% for Pd-decorated ZnO electrodes at 250 °C towards 400 ppm methylamine. The device also shows a promising response of 45% at the low temperature of 25 °C, making it a candidate sensing material for early detection of spoilage in meat-based products.