Two-dimensional photonic crystal sensor enabled by hydrophobic hydrogen-bonded organic Frameworks@Metal-Organic frameworks for trace nerve agents detection

The development of fast and accurate sensors for nerve agents holds immense significance for homeland security and public health. However, the humidity interference from ambient environments and poor sensitivity for trace nerve agents are largely unsolved problems. To overcome the problems, a humidity-independent two-dimensional photonic crystal (2-D PC) sensor is developed by exploiting UiO-66-NH2 2-D PC with excellent sensitivity coupled to a hydrophobic hydrogen-bonded organic framework (HOFs) for detection sarin simulant dimethyl methyl phosphonate (DMMP). Selective sensing results show that the HOFs@UiO-66-NH2 2-D PC sensor presents the outstanding DMMP specificity, and the limit of detection (LOD) for DMMP response of the sensor can reach 508 ± 68 ppb at room temperature. Water-resistant experiments demonstrate that the HOFs@UiO-66-NH2 2-D PC sensor shows excellent stability even under 80% relative humidity (RH). Moreover, the sensor also exhibits a rapid response/recovery time of 1 s/3 s and can maintain excellent sensing performance under heat-treatment of 200 °C and in the long-term storage (30 days). The adsorption kinetics and the hydrogen bond interaction are conducted to elucidate the mechanism of enhanced sensing DMMP properties. These results indicate the potential application of the sensor in the trace nerve agent's detection, especially in humidity environment.