Organophosphates are used as agricultural pesticides and also encountered as toxic nerve agents in chemical warfare. Accordingly, development of sensors for detecting and monitoring organophosphate vapors is highly sought after. We present a new capacitive gas sensor exhibiting remarkable specificity and sensitivity toward the organophosphate nerve gas simulants triethyl-phosphate (TEP) and dimethyl methyl phosphate and the pesticide dichlorvos. Specifically, the capacitive sensor comprises a composite porous graphene oxide matrix intercalating cobalt or nickel ions, prepared through a simple freeze-drying procedure. We demonstrate that the porous graphene oxide/metal ion electrode undergoes fast capacitance changes only upon exposure to organophosphate vapors. Moreover, the sensor exhibits extraordinary sensitivity upon interactions with TEP. Detailed mechanistic analyses, carried out in comparison to porous graphene oxide coupled to other transition metal ions, reveal that the remarkable sensing properties of the Co²⁺ or Ni²⁺/porous graphene oxide systems likely arise from the distinct mode of metal ion incorporation into the graphene oxide host matrix and substitution of metal-complexed water ligands with organophosphate molecules. The new metal ion/porous graphene oxide capacitive sensor may be employed for alerting and monitoring organophosphate gases in different environments.

中文翻译：

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多孔氧化石墨烯-金属离子复合材料，用于有机磷酸酯气体的选择性传感。

有机磷酸酯被用作农业杀虫剂，并且在化学战中也被用作毒性神经毒剂。因此，迫切需要开发用于检测和监测有机磷酸盐蒸气的传感器。我们提出了一种新型的电容式气体传感器，该传感器对有机磷酸神经气体模拟物磷酸三乙酯（TEP）和磷酸二甲酯，杀虫剂敌敌畏具有显着的特异性和敏感性。具体地，电容式传感器包括通过简单的冷冻干燥程序制备的，嵌入钴或镍离子的复合多孔氧化石墨烯基质。我们证明了多孔氧化石墨烯/金属离子电极仅在暴露于有机磷酸盐蒸气时才经历快速电容变化。此外，该传感器在与TEP相互作用时表现出非凡的灵敏度。²⁺或Ni ²⁺ /多孔氧化石墨烯系统可能是由于金属离子掺入氧化石墨烯主体基质的不同模式以及金属络合的水配体被有机磷酸酯分子取代而产生的。新型金属离子/多孔氧化石墨烯电容式传感器可用于在不同环境中警报和监视有机磷酸盐气体。