Food quality monitoring and freshness assessment are critical for ensuring food safety at a large scale. Ammonia is used as an important indicator of protein rich food spoilage state. However, current ammonia gas sensors suffer from insufficient sensitivity and selectivity, or sophisticated instrumentation, hindering their practical application in in-situ and real-time food quality monitoring. To overcome such limitations, an innovative nonporous colorimetric complex 1 has been synthesized and investigated for the detection of NH_3(g) and its volatile organic derivatives including aliphatic amines, 1,2-diaminopropane_(g), isobutylamine_(g) and ethylenediamine_(g), etc. The sensor operates colorimetrically at room temperature without energy input, with a detection limit to ammonia_(g) of 105 ppb, and show excellent reusability. The colorimetric detection mechanism involves a partial spin state change of Fe(II) ions upon exposure to amines in the gas phase. In addition, the complex was utilized as real-time monitoring of meat freshness using a smartphone. Thus, chemosensor 1 is considered as a ground breaking new-generation portable electronic nose for vapors of volatile organic compounds discrimination at room temperature.

食品质量监测和新鲜度评估对于确保大规模食品安全至关重要。氨被用作富含蛋白质的食物腐败状态的重要指标。然而，目前的氨气传感器灵敏度和选择性不足，或者仪器复杂，阻碍了它们在原位和实时食品质量监测中的实际应用。为了克服这些限制，我们合成并研究了一种创新的无孔比色络合物1 ，用于检测 NH _3(g)及其挥发性有机衍生物，包括脂肪胺、1,2-二氨基丙烷_(g)、异丁胺_(g)和乙二胺_{( G）}等。该传感器在室温下以比色方式工作，无需能量输入，对氨_(g)的检测限为 105 ppb，并表现出出色的可重复使用性。比色检测机制涉及在暴露于气相中的胺时 Fe(II) 离子的部分自旋状态变化。此外，该综合体还被用作使用智能手机实时监控肉类新鲜度。因此，化学传感器1被认为是具有开创性的新一代便携式电子鼻，用于在室温下识别挥发性有机化合物的蒸气。