Highly accurate, easily accessible room temperature wireless gas-sensing technology can be utilized to monitor food freshness in real time to prevent food fraud and spoiled food consumption, thus safeguarding humans from diseases. In this work, we coupled a high-sensitivity ammonia gas sensor with interface transmitter/gateway Bluetooth technology to produce a wireless communication system for live tracking beef freshness. Herein, we propose a chemiresistive gas sensor containing hydrothermally produced sulfur-rich WS₂/rGO hierarchical nanoflakes for gas sensing at RT. The as-developed nanohybrid was subjected to various physicochemical techniques, including XRD analysis, HR-SEM, FE-TEM, FTIR spectroscopy, Raman spectroscopy, and XPS. The sensitivity of the sulfur-rich WS₂/rGO nanohybrid towards NH₃ was twice as high as that of pristine sulfur-rich WS₂ with an LOD of 0.5 ppb and a response of 7.5% at RT. The NH₃-sensing mechanism was attributed to a negative charge donated by NH₃ on the positively charged sulfur-rich WS₂/rGO composite, which enabled it to interact with certain functional groups (SO₃H, –OH, and H₂O) and enhanced the resistance of the material. In addition, the composite had a 3.7-fold greater response to NH₃ than other VOCs and great stability after 25 cycles. Moreover, the practical application potential was also evaluated for beef freshness monitoring. This technology can be expanded to rapidly tune gas-sensing active materials via nanoengineering for various applications in wireless gas sensors, such as air-quality, automobile-exhaust, food-deterioration, and gas-leak monitoring.

中文翻译：

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使用含有边缘位点富集酸性硫的 WS2/rGO 纳米片，通过亚 ppb 级氨检测来实时跟踪牛肉新鲜度

高精度、易于使用的室温无线气体传感技术可用于实时监测食品新鲜度，防止食品欺诈和食品变质，从而保护人类免受疾病侵害。在这项工作中，我们将高灵敏度氨气传感器与接口发射器/网关蓝牙技术结合起来，生产出用于实时跟踪牛肉新鲜度的无线通信系统。在此，我们提出了一种化学电阻式气体传感器，含有水热生产的富硫 WS ₂ /rGO 分层纳米薄片，用于室温下的气体传感。对所开发的纳米混合物进行了各种物理化学技术的测试，包括 XRD 分析、HR-SEM、FE-TEM、FTIR 光谱、拉曼光谱和 XPS。富硫WS ₂ /rGO纳米杂化物对NH _{3的灵敏度是原始富硫WS 2}的两倍，LOD为0.5 ppb，室温下响应为7.5%。 NH ₃传感机制归因于NH ₃在带正电荷的富硫WS ₂ /rGO复合材料上提供负电荷，这使其能够与某些官能团（SO ₃ H、–OH和H ₂ O）相互作用。 ）并增强了材料的电阻。此外，该复合材料对NH _{3 的}响应比其他VOC高3.7倍，并且在25次循环后具有良好的稳定性。此外，还评估了牛肉新鲜度监测的实际应用潜力。该技术可以扩展到通过纳米工程快速调节气敏活性材料，用于无线气体传感器的各种应用，例如空气质量、汽车尾气、食品变质和气体泄漏监测。