活体植物中β-胡萝卜素分子的二级拉曼散射谱

Secondary Raman Spectrum of β-carotene Molecule in Living Leaf of French Phoenix Tree

利用显微拉曼光谱技术对从法国梧桐树新鲜采集得到的树叶做了测试分析 ,在可见光 5 14 5nm激发下 ,不对样品做任何提纯 ,直接得到了树叶中 β 胡萝卜素分子的一级和二级拉曼光谱。根据对 β 胡萝卜素分子拉曼散射位于 2 0 0 0～ 310 0cm-1之间和 2 0 0 0cm-1以下谱线的仔细分析对比 ,得到了二级拉曼谱和一级谱的倍频、和频关系。实验研究表明 ,控制样品表面的激光强度和信号积分时间 ,不破坏活体树叶中的分子结构和构象 ,这为研究植物在不同的环境生长状况提供一种实时实地测量技术。

Under visible incidence light 514.5 nm,the Raman scattering spectrum from the β-carotene molecule in the leaf was directly obtained after it was immediately collected from French phoenix tree without any preparing the sample but cleaning. It is very easy to collect the secondary Raman lines addition to the first Raman spectrum in situ by micro Raman. By careful comparing and analyzing the Raman lines between 2 000-3 100 cm -1 and below 2 000 cm -1 regions,we obtained the correlated relation of the first and secondary Raman lines.The study results indicated that there is no damage to the structure and configuration of β-carotene molecule in the live leaf by controlling laser power on the sample surface and integrating time for Raman signal,but large power laser or long time irradiation on the live sample would cause very strong fluorescence background in Raman spectrum which indicated that there is a photo damage in the center of photo reaction.The Micro Raman would become one of possible in situ methods for investigating live plant molecules growing up in different environment.At last we proposed and discussed the advantages and limits in micro Raman when it is applied to investigating live molecules in botany field.