【作者】 王立明；

【导师】 贺胜男；

【作者基本信息】 安徽大学 ， 光学工程， 2024， 硕士

【摘要】 荧光淬灭传感技术是一种利用荧光共轭聚合物“分子导线”效应的痕量检测技术,通过选用不同的荧光共轭聚合物材料可实现对不同物质如毒品、爆炸物的检测。为提高荧光淬灭传感技术的灵敏度和稳定性,研制更高性能的荧光共轭聚合物薄膜和开发性能更优良的传感基底是该技术的关键。分布式反馈(Distributed Feedback,DFB)微腔能够将光限制在光栅槽内部形成分布式反馈效应,从而提高对目标物传感的灵敏度。虽然有研究人员在荧光淬灭传感技术中引入DFB微腔制成DFB光栅传感器,但这些研究大多采用体积大、功耗高的脉冲激光器作为泵浦光源,并不适用于传感器集成化,且对DFB光栅传感器性能的影响因素尚未深入研究。针对该技术的传感器工程化需求,本文开展了DFB光栅对荧光淬灭的增强机理、DFB光栅传感器结构参数等因素对传感性能的影响、DFB光栅传感器稳定性等问题的理论仿真与实验研究。具体研究内容和结论如下:(1)采用COMSOL软件对DFB光栅传感器进行了结构设计与优化,设计并制作了4种槽深、4种膜厚的一维和二维DFB光栅传感器。采用激光二极管作为泵浦光源,搭建了荧光淬灭传感光路,开展了爆炸物二硝基甲苯(Dinitrotoluene,DNT)检测实验。(2)定义了三类DFB光栅传感器的性能表征方法,开展了光栅槽深、聚合物薄膜厚度、泵浦光功率对传感器性能影响实验,结果表明旋涂1 mg/ml Poly(9,9-dioctylfluorene-alt-bithiophene)即PFOT溶液的200nm槽深一维DFB光栅传感器性能最佳,60s内对DNT蒸气淬灭效率达到98.3%。开展了一维和二维DFB光栅传感器性能的对比实验,结果表明在相同条件下二维DFB光栅传感器探测灵敏度、响应速度、荧光激发的稳定性等性能更加优良。(3)基于实验结果,对DFB光栅传感器的集成化、微型化进行了初步方案设计,利用流体力学数值模拟软件Fluent对采样气室结构等重点区域进行了分析与优化。本文研究结果为实现基于DFB光栅的荧光淬灭传感技术工程化提供了有力支持,为传感器设计、制作与集成提供了重要参考。更多还原

【Abstract】 Fluorescence quenching sensing technology is a trace detection technology that utilizes the“molecular wire”effect of fluorescent conjugated polymers,and by choosing different fluorescent conjugated polymer materials,it can realize the detection of different substances such as drugs and explosives.In order to improve the sensitivity and stability of the fluorescence quenching sensing technology,the development of higher performance fluorescent conjugated polymer films and better sensing substrates is the key to this technology.Distributed Feedback(DFB)microcavities are able to confine light within the grating grooves to create a distributed feedback effect,which improves the sensitivity of target sensing.Although some researchers have introduced DFB microcavities into fluorescence quenching sensing technology to make DFB grating sensors,most of these studies have used pulsed lasers,which are large in size and high in power consumption,as the pump light source and are not applicable to sensor integration,and the factors affecting the performance of DFB grating sensors have not been studied in depth.For the sensor engineering needs of this technology,this paper carries out the theoretical simulation and experimental research on the enhancement mechanism of DFB grating on fluorescence quenching,the influence of factors such as structural parameters of DFB grating sensors on sensing performance,and the stability of DFB grating sensors.The specific research contents and conclusions are as follows:(1)The structure design and optimization of DFB grating sensors were carried out using COMSOL software,and one-dimensional and two-dimensional DFB grating sensors with four groove depths and four film thicknesses were designed and fabricated.A fluorescence quenching photosensitive path was constructed using a laser diode as the pump light source,and an experiment was conducted to detect the explosive Dinitrotoluene(DNT).(2)The performance characterization methods of three types of DFB grating sensors were defined,and experiments on the effects of grating slot depth,polymer film thickness,and pump optical power on the sensor performance were carried out,and the results showed that the 200 nm slot depth one-dimensional DFB grating sensor with spin-coated 1 mg/ml Poly(9,9-dioctylfluorene-alt-bithiophene),i.e.,PFOT solution,performed the best.The sensor performance is optimal,and the quenching efficiency of DNT vapor reaches 98.3%in 60s.Comparative experiments on the performance of one-dimensional and two-dimensional DFB grating sensors were carried out,and the results showed that the two-dimensional DFB grating sensors had better performance in terms of detection sensitivity,response speed,and stability of fluorescence excitation under the same conditions.(3)Based on the experimental results,a preliminary scheme was designed for the integration and miniaturization of DFB grating sensors,and key areas such as the structure of the sampling gas chamber were analyzed and optimized using Fluent,a numerical simulation software for fluid dynamics.The results of this paper provide strong support for the engineering of fluorescence quenching sensing technology based on DFB gratings,and provide an important reference for sensor design,fabrication and integration.更多还原