基于敏感膜/条形薄膜光波导传感元件的设计与光谱仪连用检测系统研究

Strip optical waveguide thin film has smaller cross section and larger refractive index with potential applications in high sensitive biochemical sensor fields, also favorable in integration and micromation. Metalloporphyrins change their colors when exposed to amines and aromatic compounds, therefore they are promising OWG sensitive materials. In this project ①, high sensitive strip OWG sensing element was fabricated with nano thin films ,which were prepared by high refractive index materials such as TiO2 ; synthesized or selected metalloporphyrins were immobilized onto the strip OWG sensing film, to achieve “sensitive layer/strip optical thin film layer/ optical OWG sensing element”. ②Previous OWG testing apparatus could only detect the strength of output light in certain wavelengths; New type of testing system will be achieved by combining the OWG sensing element with spectrophotometer, Xenon light source, chromatographic column. And with this system, changes of output-light-strength following with wavelength( 200-1100 nm) can be detected when sensitive element interact with inorganic gases and volatile organic compounds such as amines, aromatics et al.; new methods will be discussed about the quantitative and qualitative recognition of analytes; thick-film-type gas sensitive electrode will be prepared, and detected using gas-sensing tester; comparative studies will be carried out about the light-electric sensitivity and sensing mechanism. The key scientific problems and solving measurements in this project will make contribution to design optical sensitive element and new type of sensing technology, also to promote the development and industrialization of the new type of optical sensors.

条形薄膜光波导（OWG）具有更小的横截面、更大的折射率差，适用于高灵敏生化传感器，并有利于微型化和集成化。金属卟啉与胺和芳香族类化合物发生特异变色反应，是极具潜力的OWG传感器敏感材料。本项目①将高折射率TiO2等做成高灵敏条形薄膜OWG；将合成或筛选金属卟啉做纳米薄膜固定在条形薄膜表面，研制敏感层/条形薄膜导波层/玻璃OWG传感元件。②原OWG系统只检测某一波长下输出光强度随时间的变化；将OWG传感元件与光谱仪、氙灯光源、色谱柱等组合开发新型OWG测试系统。测定敏感层与胺类等挥发性有机物及无机气体（单独和混合）相互作用时输出光强度随波长（200-1100nm）的变化，探讨定量和定性识别被测物新方法；制备厚膜型气敏电极并用气敏测试仪检测，相互比较并探讨OWG元件气敏机理。所以本项目提出关键科学问题及解决必将为新型传感器设计及其技术的探讨提供研究数据，有助于推动新型光学传感器开发和产业化。

敏感材料是化学传感器核心部位，最近鉴于响应快等优点，卟啉及金属卟啉等作为敏感材料在氨气检测以及肺癌呼出挥发性有机物中特定标志物的检测等临床医学方面进行实验和理论研究并取得了令人满意的成果。.该基金资助下，合成或筛选了四苯基卟啉和八乙基卟啉及其与Zn，Cu，Ni，Co，Fe等的配合物，通过UV-Vis、FT-IR、XRD、XPS等进行表征；通过SEM和AFM等方法分析敏感膜表面及其被测物相互作用前后形态变化，并确定其溶液或薄膜中聚集（H或J）状态。.用敏感材料作纳米薄膜，研制“敏感层/条形（平面）薄膜导波层/Sn掺杂（K+）玻璃复合光波导（OWG）传感元件”，检测了二甲胺、三甲胺、乙醇、苯、二甲苯等挥发性有机物及SO2,H2S,NH3等气体。结果显示，“条形薄膜OWG”元件灵敏度比平面光波导元件高一到两个数量级。另外，将酸碱指示剂固定在正硅酸乙酯胶体中研制的OWG传感器在水溶液中保持稳定30天、可重复使用，能检测到水中浓度为0.0008μg/L的二甲胺。研制的敏感元件应用到“油漆和羊肉新鲜度”检测，结果与国标做比较，证实OWG气敏元件具有较好的应用前景。.比较敏感材料的光和电气敏响应、分子结构、薄膜表面形貌，分析和探讨其气敏机理；分别研究并总结了卟啉meso位苯环对位取代基以及不同金属对OWG敏感元件气敏性和选择性的影响。.通过分子动力学模拟计算、吸收光谱和OWG检测系统，研究了卟啉取代基及Zn，Cu，Ni，Co等过渡金属对OWG元件气敏性的影响。结合吸光度变化和分子动力学模拟，讨论了卟啉分子在薄膜状态的聚集行为以及与H2S、HCl、CO2和NO2气体的相互作用机理。色谱柱、紫外可见近红外波段的光源、光谱仪与OWG传感系统连用方面，取得了一定成果。.研究成果已得到了国内外同行专家的认可和肯定，在国内外知名刊物已发表34篇论文（27篇为SCI）；培养博士3名，硕士10名，都通过论文答辩。1名博士现在清华大学作博士后；4名硕士分别考入清华大学等国内名校攻读博士学位。