基于顶空及SERS结合的新鲜植物挥发性气体研究

Plants volatile organic compounds (PVOCs) are involved in a range of ecological functions, including sterilization, bacteriostasis, repelling insects, attraction of pollinators thus promoting seed propagation, impeding the growth, and development of the other plants to improve their viability, and lastly it is conducive to the healthiness of body & mind of people. It has received much attention in recently years. The gas chromatography/mass spectrometry is the most effective method of analyzing PVOCs nowadays. The method can be used as qualitative and quantitative analysis for all compositions or designated compositions in the samples. It is an effective method to determine molecular structure of compounds with high sensitivity. However problems associated with the analytical method, such as long measurement time, involving many steps of indirect measurements, expensive equipment, etc, which make the detection system less attractive. Thus, an inexpensive, quick and in situ detection method for POVCs is urgently needed. Surface-enhanced Raman scattering (SERS), which can offer rich fingerprint information, the higher detection sensitivity, and lower cost is widely used in the physical, chemical, biological and other areas. The project is based on the research group's original work of prepared nano-silver particles, nano-silver film by electrolysis methods and by microwave method. Further improvement may be required for the preparation of nano-silver particles, nano-silver film that have SERS effect for PVOCs of Allium L, Zingiber Boehm, Amomum Roxb coming from Yunnan province. One objective is to set up surface-enhanced Raman spectrum database of Allium L, Zingiber Boehm, Amomum Roxb. These three species of plants can be rapidly identified with chemometrics methods. Another objective is exploring the feasibility of using PVOCs SERS spectrum in the classification of plants. If the method is effective, it will provide a new method for the classification of plants, and provide a new way for a more comprehensive utilization of plants

由于植物挥发性有机物（PVOCs）具有杀菌、抑菌、驱虫生态功能；具有吸引传粉者促进种子传播及抑制其他植物的生长发育来提高自身的竞争能力；具有调节身心及医疗保健功能；因而越来越受到人们的重视。 目前分析植物挥发性有机物（PVOCs）最有效的方法是气相色谱/质谱联用仪。然而该方法存在如测量时间长，非直接测量,仪器费用高等问题。表面增强拉曼散射（SERS）由于能提供丰富的指纹信息、检测灵敏度高、廉价已在物理学、化学、生物学等学科得到广泛的应用。本项目在课题组原有的工作基础上，即电解法、微波法制备稳定、高效的正、负电性胶态纳米银粒子, 纳米银膜的基础上，进一步完善或试制对云南葱属、姜属、豆蔻属植物的PVOCs有SERS效应的纳米银结构。以建立云南省葱属、姜属、豆蔻属植物表面增强拉曼光谱图库为目标，结合化学计量学方法，达到这三属植物的快速鉴定。并利用PVOCs的SERS谱探索植物光谱分类的可行性。

目前分析植物挥发性有机物（PVOCs）最有效的方法是气相色谱/质谱联用仪。然而该方法存在如测量时间长，非直接测量、仪器费用高等问题。拉曼散射、表面增强拉曼散射（SERS）由于能提供丰富的指纹信息、检测灵敏度高、廉价已在物理学、化学、生物学等学科得到广泛的应用。本项目在课题组原有的工作基础上，即电解法、微波法制备稳定、高效的正、负电性胶态纳米银粒子, 纳米银膜的基础上，制备了对云南葱属植物的PVOCs有SERS效应的纳米银结构。建立了云南省葱属、姜科植物的拉曼、表面增强拉曼光谱图库，结合化学计量学方法，达到葱属、姜科植物的快速鉴定。.对葱属植物，通过大量的实验筛选出对葱属植物的挥发性物质有增强效应的基底。该基底对葱属植物挥发性物质的增强具有高重复性、高均匀性、高稳定性。采用顶空瓶在常温常压下收集挥发物，将挥发物用注射器注入纳米银胶中，进行SEＲS 测量。建立了常温常压下快速检测新鲜葱属植物主要挥发性气体的方法。.对姜科植物，由于姜科植物的挥发性物质不溶于水，不易吸附的纳米银的表面。探索出了一种不需要提取，在常温下就能对其挥发性物质进行研究的方法-油细胞原位拉曼光谱研究的方法。将植物徒手切片后用水装片，将切片置于显微镜下，调焦后可清楚的见到细胞结构，寻找近圆形的油细胞，将激光聚焦油细胞，得到油细胞中精油的拉曼光谱。.利用SPSS软件对所获得的葱属植物的SERS谱，姜科植物油细胞拉曼谱进行聚类分析。.利用量子力学从头算的原理，使用Gaussian’03软件包，计算了标样的拉曼光谱，并借助计算拉曼光谱对所获得的标样的拉曼谱，葱属植物SERS谱及其姜科植物油细胞精油的拉曼光谱进行指认。