In recent years, with the rapid development of information technology such as the Internet of Things, gas sensors, as gas signal collection devices, have played a vital role in environmental monitoring, industrial and agricultural production, food safety management, medical health diagnosis and air quality monitoring. In industrial production, acetone and ammonia are common chemicals that can leak or exceed safe concentrations, necessitating timely detection and alarm systems to ensure worker safety. Therefore, it is imperative to detect the content of acetone and ammonia, which are widely used and toxic gases. In this paper, a wireless gas sensor based on lanthanum ferrite (LaFeO3)/zinc oxide (ZnO)/reduced graphene oxide (rGO) was proposed and designed to detect acetone and ammonia concentrations at room temperature. The gas sensor with perforations is optimized using HFSS software, and the antenna is fabricated using an engraving machine. Subsequently, the nanocomposite material is coated onto the antenna to complete the gas sensor. The microstructure of lanthanum ferrite/zinc oxide/graphene is characterized and analyzed. Test results demonstrate that the sensor operates within a range of 300 ppm ∼ 1000 ppm for acetone concentration, exhibiting an amplitude change of 16.28 dB and a sensitivity of 0.023 dB/ppm. Furthermore, when operating stably within a range of 150 ppm ∼ 800 ppm for ammonia concentration, the sensitivity of the sensor reaches 0.328 MHz/ppm. Compared to traditional gas sensors, this gas sensor offers advantages such as high detection accuracy, minimal environmental interference factors, excellent selectivity, and prolonged lifespan; presenting promising prospects for detecting toxic gases in laboratories and chemical factories.
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