苋菜红表面增强拉曼光谱的密度泛函理论研究  

Density Functional Theory Study on Surface-Enhanced Raman Spectral of Amaranth

作　　者：逯美红[1] 贾娟 雷海英[3] 王志军[1] 张竺立 程旭丽 吴艳波[4] LU Mei-hong;JIA Juan;LEI Hai-ying;WANG Zhi-jun;ZHANG Zhu-li;CHEN Xu-li;WU Yan-bo(Department of Electronic Information and Physics,Changzhi University,Changzhi 046011,China;College of Science,Inner Mongolia University of Technology,Huhhot 010000,China;Department of Biological Sciences and Technology,Changzhi University,Changzhi 046011,China;Institute of Molecular Science,the Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education,Shanxi University,Taiyuan 030006,China)

机构地区：[1]长治学院电子信息与物理系,山西长治046011 [2]内蒙古工业大学理学院,内蒙古呼和浩特010000 [3]长治学院生物科学与技术系,山西长治046011 [4]山西大学分子科学研究所,教育部化学生物学与分子工程重点实验室,山西太原030006

出　　处：《光谱学与光谱分析》2020年第6期1833-1838,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21201024);山西省高等学校教学改革创新项目(J2018182);山西省高等学校大学生创新创业训练项目(2018594);山西省高等院校科技开发项目(201802106和2010128)资助。

摘　　要：苋菜红(Amaranth)作为一种人工合成食品添加剂,常被添加于汽水、山楂和糖果等当中,但苋菜红是由煤焦油中分离出来的苯胺染料为原料制成,过量食用会导致基因突变甚至致癌,严重危害身体健康。因此,对其检测至关重要。表面增强拉曼光谱技术具有样品前处理简单、分析速度快和准确性高等优点,已在化学、生物和医学领域越来越显示出巨大的潜能。目前,用拉曼光谱技术对苋菜红检测的理论与实验研究还未见报道。而对拉曼光谱及表面增强理论机理的研究可以为在食品中检测及鉴定苋菜红提供可靠的科学依据。所以利用密度泛函理论全面探究苋菜红的表面增强拉曼机理并与实验结果进行对比,对食品中的苋菜红检测研究有很好的预测及指导意义。一方面,利用共聚焦显微拉曼光谱仪对苋菜红粉末进行拉曼光谱检测,得到其拉曼光谱;另一方面,搭建苋菜红分子结构,并基于密度泛函理论对分子结构进行优化处理,从前线轨道、静电势、极化率及自然键轨道布局分析四个角度进行计算分析,得出偶氮基团处(-N15=N16-)是苋菜红分子与Ag原子配位的最佳位置。在此基础上,使用B3LYP/6-31++G(d,p)基组(C,H,O,N,S,Na)和B3LYP/Sdd基组(Ag)对苋菜红分子与1个Ag原子及3个Ag原子团簇的复合物(Amaranth-Ag1,Amaranth-Ag3)进行结构优化和表面增强拉曼光谱计算。将苋菜红分子的实验与理论拉曼光谱进行比较,发现二者吻合较好,且在1228,1329,1467和1529 cm-1处苋菜红分子的拉曼活性很明显。另外,苋菜红与Ag的复合物有明显的拉曼增强效应,增强效果随着Ag原子个数的增多而愈加明显,不仅拉曼光谱的峰值个数有增多,而且其对应光谱峰位强度也有增强。进一步通过振动模式的归属,得到鉴定和识别苋菜红的拉曼特征峰。该研究为利用表面增强拉曼光谱技术检测食品中的苋菜红提供了一定的实验�Amaranth is a synthetic food additive.It is often added to soda,hawthorn and candy,etc.However,Amaranth is made from the coal tar isolated by the benzene dye as raw material,and excessive consumption will lead to genetic mutations and even cancer,which is harmful to health.Therefore,the detection of Amaranth is important and necessary.Surface-enhanced Raman spectroscopy has the advantages of simple pre-processing,rapid analysis and high accuracy for samples,which has been increasingly shown great potential in the fields of chemistry,biology and medicine.At present,the theoretical and experimental research on Amaranth with Raman spectroscopy technology has not been reported.The study of Raman spectroscopy and the theoretical mechanism of surface enhancement can provide a reliable scientific basis for the detection and identification of Amaranth in food.Therefore,the study on the surface-enhanced Raman mechanism of Amaranth and compare it with the experimental results using the density functional theory is necessary.It has a good prediction and guiding significance for the detection of Amaranth in food.On the one hand,Amaranth was detected by using micro-confocal Raman spectrometer.On the other hand,the structure of Amaranth was built,and Density Functional Theory was used to optimize the molecular structure and calculate the front-line orbit,electrostatic potential,polarization and natural bond orbital analysis.And the azo group(-N15N16-)is the best position for Amaranth to coordinate with Ag atom.The optimum structure and surface-enhanced Raman spectra of Amaranth-Ag1,Amaranth-Ag3 complexes molecules were calculated by using B3 LYP function with 6-31++G(d,p)(C,H,O,N,S,Na)base set and Sdd(Ag)base set,receptively.The results showed that the experimental results at 1228,1329,1467 and 1529 cm-1 were in good agreement with the theoretical results and the Raman activity of Amaranth molecule was obvious.Raman enhancement effect of Amaranth-Ag complex was significant and the Raman enhancement effect increases with the nu

关 键 词：苋菜红 表面增强拉曼光谱 密度泛函 分子静电势 

分 类 号：O437.3[机械工程—光学工程]