AE的分布及其在ZnO NPs作用下的颜色与光谱分析

Distribution of Aloe-Emodin and Its Color and Spectral Properties under the Influence of ZnO NPs

氧化锌纳米粒子(ZnO NPs)是应用非常广泛的一种多功能无机材料,主要应用于化妆品、涂料、抗菌等领域。ZnO纳米粒子的大量使用增加了与生物接触的机会,可能会对生态环境产生一定的影响。芦荟是百合科常绿多肉质草本植物,具有重要的观赏和药用价值。芦荟大黄素(Aloe-emodin,AE)是芦荟中重要的色素分子,也是芦荟作为药用植物的重要有效成分。因此,以芦荟为实验对象,利用荧光显微镜通过纵向切片的方法观察了AE在叶片中的分布,较横向切片法更为全面、清晰地揭示了AE在叶片中的分布情况。通过荧光光谱结合颜色变化研究了ZnO纳米粒子与AE的相互作用。结果表明,在黑暗条件下,ZnO纳米粒子处理后溶液颜色由淡黄色逐渐变成橙色;紫外光照射使得AE溶液颜色变化加快,在相同的作用时间内,溶液颜色变得更深,由淡黄色逐渐变成橙红色。光谱研究发现,AE的荧光光谱有四个发光峰,分别是500,540,580与630nm,与对照组相比,ZnO纳米粒子引起芦荟大黄素540和580nm两个荧光峰的相对强度发生变化,随着ZnO纳米粒子作用时间的增加,I540/I580比值逐渐增大。

Zinc oxide nanoparticles(ZnO NPs)have unique physical and chemical propertiesand important application values in many fields,which has also been resulted the consequence that it was released into different environment,and increased the interaction with creatures,which is the most important aspect of the toxic effects of ZnO NPs.Aloe is a lily family of evergreen and fleshy herbs,which has important ornamental and medicinal value,Aloe-emodin(Aloe emodin,AE)is an importantpigment molecule in aloe,which is also an important active ingredient of aloeasa medicinal plant.In this work,from a new perspective,the distribution ofAE in leaves was investigated through the longitudinal slicing method with fluorescence microscopy,and which was comprehensively understood,and then the interaction between ZnO NPs and AE was studied.The changes of the color of AE andits fluorescence spectra under the influence of ZnO NPs were observed and analyzed.The results showed that the trend of the color change of AE solution was from light yellow through orange yellow,orange to orange red;moreover,compared with the control group,the ZnO NPs accelerate the changes of the relative intensity of the main the emission peaks located at 540 and 580 nm,increased the ratio of I 540/I 580.The above results indicate that ZnO NPs have obvious negative effects on AE,which provides more information for a comprehensive evaluation of the bio-risks of ZnO NPs on aloe and other related plants.