基于金属-有机框架材料的高灵敏度痕量爆炸物波导传感器研究

Due to the elevated development of explosive preparation and hidden terrorist activities, aviation safety faces the severe challenges in real-time detection of explosives. In this aspect, developing new sensing ideas and methods for the explosive detection in aviation safety are always highly urgent. In this proposal, we designed a porous metal-organic framework material (MOF) containing organic dipole molecule as sensing material for trace explosive detection. Mach-Zehnder waveguide trace explosive sensor was fabricated, in which the sensitive MOF was used as the upper cladding material. When the waveguide sensor was exposed to explosive gas, the interaction between the electron-deficiency explosive gas and electron-rich dipole molecular in upper cladding layer changed the microscopic dipole moment and polarizability of dipole molecules. This change in molecular microscopic property changed the refractive index of sensitive upper cladding layer and in further modulated the phase of optical signal in core layer to realize the sensing of trace explosive in waveguide. Due to the high porosity, large surface area and ordered porous structure of MOF for the permeation and transmission of explosive gas in upper cladding layer, it contributed to the fast sensing with high sensitivity. Refractive index sensing in waveguide sensor was as sensitive as 10-7 magnitude and undisturbed to environment, which was prone to realize the explosive sensing in the magnitude of part per trillion. Meanwhile, this waveguide device was easy to integration and encapsulation, paving the way for the idea of Lab on Chip.

随着爆炸物制备和恐怖活动隐匿水平的不断提高，航空安检面临更加严峻的挑战，建立和发展新的航空爆炸物探测技术以应对日益严峻的航空安全需要是人们迫切追求的。本项目拟设计以有机偶极分子为框架的多孔金属-有机框架材料（MOF），并以此作为波导传感包层，制备Mach-Zehnder型痕量爆炸物波导传感器，通过缺电子的爆炸物蒸汽与包层MOF中的偶极分子相互作用改变分子的微观极化率，进而改变包层传感区域的折射率，最终调制芯层的光场传输，实现痕量爆炸物在光波导器件上的传感功能。MOF高孔隙率、大比表面积、孔道规则有助于爆炸物气体的渗透与传输，实现高灵敏度和快速传感。波导传感器折射率传感精度高达10-7且不易受外界环境干扰的优势有望实现高达part per trillion的超高灵敏度爆炸物检测。同时，器件易于集成和封装，可为“片上实验室（Lab on Chip）” 的实现提供重要思路和技术基础。

随着爆炸物制备和恐怖活动隐匿水平的不断提高，航空案件面临着更加严峻的挑战，本项目针对航空安全中的痕量爆炸物气体2，4-二硝基甲苯（DNT）的检测，在爆炸物敏感材料及其器件的折射率传感方面开展了系统的研究工作。.在材料方面，制备合成了14个有机偶极分子染料，筛选了其中的偶极分子分别用于折射率传感和非线性光学应用；制备了ZIF-8, ZIF-67, HKUST-1等三种金属有机框架材料，对材料的多孔结构和气体吸附性能进行了系统的表征，筛选了ZIF-8作为波导/光纤DNT气体检测的敏感薄膜材料。.在器件方面，在光纤和聚合物波导分别制作了mach-zehnder干涉仪(MZI)，结合ZIF-8材料优异的DNT气体吸附性能，在光纤MZI器件上实现了对DNT的高灵敏度检测，响应时间<30秒。在聚合物波导上制作了MZI结构的紫外光探测器，对低功率的紫外光（10μw/cm2）进行了探测，折射率灵敏度>10000nm/RIU。制备了以ZIF-8为敏感薄膜的聚合物MZI爆炸物传感器，器件性能正在进一步优化中。采用有机偶极分子作为激光增益材料，设计并制作了微流激光传感器，在乙醇溶液中实现了对DNT低至10-8 mol/L的高灵敏度和大动态范围（10-8-10-4mol/L）快速检测。.综上所述，成功制备了可以快速检测DNT气体爆炸物的ZIF-8光纤MZI传感器，聚合物波导MZI紫外光传感器和微流激光DNT传感器，完成本项目申请书所列研究目标。所研制的实验室样品波导器件尺寸小，易于集成，具有实际应用价值；而光纤MZI器件制作工艺更简单，已初步实现了小批量生产的能力，进一步的检测系统优化后有希望投入传感市场应用。