激光诱导荧光探测气溶胶装置的研制及实验研究

基于激光诱导荧光原理研制出一套激光诱导荧光探测气溶胶的装置。该装置采用Nd:YAG脉冲激光器产生355 nm波长脉冲激光，经过引导后进入样品池，激发出的荧光被系统收集后进入高分辨率光栅光谱仪，得到样品的荧光光谱图。选用还原型辅酶I（NADH）和核黄素两种典型的生物荧光物质对系统的性能进行测试，在355 nm激光激发下，获取了还原型辅酶I（NADH）、核黄素荧光光谱图；研究了样品浓度对于荧光光谱强度的影响，结果表明在低浓度范围荧光强度与浓度呈线性关系；考查了激光能量对荧光强度的影响，在一定能量范围荧光强度与激光能量呈线性关系，但当激光能量达到一定值后荧光强度会发生饱和。该装置所建立的生物性物质荧光数据库有利于了解和掌握生物荧光特性，对于进一步实现生物气溶胶远距离探测具有重要意义。

Development and Experiment Results of Laser Induced Fluorescence Aerosol Detection Device

Based on the principle of laser induced fluorescence, a laser induced fluorescence aerosol detection device is developed. The device uses the Nd:YAG pulsed laser in 355 nm wavelength, and the laser is guided to sample cell, then the fluorescence is collected into the high resolution grating spectrograph, finally the fluorescence spectrum is displayed. Two typical biological fluorescent substances reduced coenzyme I (NADH) and riboflavin are chosen as samples to test the performance of the device. Under the excitation of the laser in 355 nm wavelength, the reduced coenzyme I and riboflavin fluorescence spectrum are obtained. The influence of concentration on the fluorescence intensity of riboflavin is studied experimentally, and the results show that fluorescence intensity has a linear relation with the riboflavin concentration during the low concentration range. The influence of the laser intensity is also studied, the results show that fluorescence intensity changes linearly with laser power within the limits, but the fluorescence intensity saturation will happen when the laser power reaches a certain value. The biological fluorescent materials database given by the laser induced fluorescence method is helpful to understand and grasp the biological fluorescence characteristics and is of significance to remote sensing of biological aerosols.