【作者】 杜银霄；

【导师】 莫育俊；

【作者基本信息】 河南大学 ， 光学， 2003， 硕士

【摘要】 拉曼光谱属于分子光谱。因为每个分子产生的拉曼光谱谱带的数目多少、位移大小、谱带强度与形状都直接与分子的振动和转动相关，所以研究分子的拉曼光谱可以得到分子结构的相关信息，从而可以利用这种技术进行药物检测、痕量分析以及表面振动谱的探测研究等。随着激光光源频率范围的不断扩展，光探测手段的不断丰富，拉曼光谱的检测灵敏度获得了极大的提高；同时，拉曼光谱与其他现代分析手段（如IR、EELS、AES、XPS、SEM、TEM、AFM、SNOM、MS、CS等）的结合，为拉曼光谱技术带来了更加广阔的应用前景。维生素是人体维持正常生理功能所必需的一类营养物质。由于它对于人体的不可或缺性，一直是医学、电化学和生物无机化学非常感兴趣的研究对象。我们利用拉曼光谱技术来研究维生素就是想通过掌握维生素分子结构的相关信息，进而深入研究维生素在人体内的吸收过程，从而对维生素在人体内所起的作用进行检测和分析。表面增强拉曼散射（SERS）是一项新的拉曼光谱技术，它大大提高了被分析物质的拉曼散射强度，达到了单分子检测的灵敏度，是我们进行分子结构研究的主要手段。本论文由四部分组成，第一部分介绍了SERS的实验现象、拉曼光谱技术的优势以及SERS的研究现状。论文中，我们对SERS效应在实验中的主要特点进行了总结，描述了SERS的增强机制与SERS理论模型的发展概况。指出目前普遍接受的观点是电磁增强和化学增强机制同时存在，只是两者在不同的实验体系中所占的比重不同。第二部分研究了SERS的活性衬底并介绍了我们的实验装置和样品的制备方法。因为在实验中所选衬底是否具有活性直接决定了样品SERS效应的强弱，我们对一些经常在实验中用到的SERS活性衬底进行了总结，详细描述了活性衬底的制备过程，并讨论了如何判定衬底是否具有活性。<WP=3>第三部分对维生素K3（VK3）进行了SERS研究。在实验中，首次对VK3的拉曼特征峰进行了指认和归属，并利用VK3分子结构的相关信息，得出VK3分子与银表面发生了强的相互作用的结论。最后，我们用电荷转移模型对实验结果进行了解释，并对VK3分子振动模式的识别进行了验证，初步完成了VK3的SERS研究，为今后利用SERS技术对VK3进行药物检测以及痕量分析方面的应用提供了依据。第四部分对维生素C（VC）进行了SERS研究，并通过对单壁碳纳米管/聚合物进行混合成份的定量分析来说明拉曼光谱技术的一些实际应用。在实验中，首次对VC的拉曼特征峰进行了指认和归属，进而获得了VC分子结构的一些结论，初步完成了VC的SERS研究。另外，我们通过单壁碳纳米管/聚合物的拉曼光谱积分结果，对其所遵循的定量分析规律进行了讨论更多还原

【Abstract】 Raman spectrum belongs to molecular spectrum. Because the vibration and rotation of molecule can induce change of Raman shift, Raman intensity and shape of Raman band, the study of Raman spectrum can provide information of molecular structure, so we can do research in druggery detection, trace analysis and vibrational spectrum investigation of molecules through the study of Raman spectrum. With the expansion of frequency range of modern laser and the enrichment of light detection method, sensitivity of Raman spectrum has made great progress. Combined with other analytic methods such as IR, EELS, AES, XPS, SEM, TEM, AFM, SNOM, MS, CS, etc., Raman spectrum is sure to have a broader field of application.Vitamin is a kind of nutriment which is necessary for human body to maintain normal physiological function. Because of its indispensability to human body, vitamin has been an interesting research object in medical science, electrochemistry and inorganic chemistry. If the structural and related information of vitamin is clear, we can do thorough research in vitamin absorption process in human body. So the purpose of our research is to analyze and detect the role of vitamin in human body through the study of Raman spectrum. Surface-Enhanced Raman Scattering(SERS) is a new technique of Raman spectrum which can greatly enhance Raman intensity. This technique has reached the level of monolayer detection and was applied as a main investigation method of molecular structure in our experiment.This thesis consists of four parts. In the first part, we gave an introduction of SERS, the advantages of Raman spectrum and status of SERS research were discussed. We summarized the characteristics of SERS effect in experiment and described the mechanisms of SERS and theoretic models of it. It’s an accepted view that the<WP=5>mechanism of electromagnetic enhancement and the mechanism of chemical enhancement are both in existence. But which one is more important in different experiment, specific condition must be accounted for.In the second part, we investigated the active substrates of SERS and introduced the instruments in experiment and the preparation of samples. Because Raman intensity is related to activity of substrate in experiment, we summarized active substrates of SERS which were often employed in experiment, and then we described the preparation of active substrates in detail, we also discussed how to judge activity of substrates in the end.In the third part, we did research in vitamin k3 by SERS. Assignments of the Raman band for vitamin k3 molecules were presented for the first time. We concluded that a strong interaction lied between Vitamin K3 molecules and silver surface through analyzing the information of molecular structure. Finally, we explained the experimental results by the model of charge transfer and verified identification of vibrational mode of vitamin k3 molecules. We accomplished the first step of SERS research for vitamin k3 molecules. Our research provided information for the application of SERS techniques in druggery detection and trace analysis.In the fourth part, we did research in vitamin C by SERS, and then we accounted for application of Raman spectrum by quantitative analysis of Conjugated Polymer/Single-Walled Carbon Nanotubes. Assignments of the Raman band of vitamin C molecules were presented for the first time and some conclusions about vitamin C molecules were drawn. We accomplished the first step of SERS research of vitamin C molecules. In addition, we discussed the rule of quantitative analysis by the integral result to Raman spectrum of Conjugated Polymer/Single-Walled Carbon Nanotubes更多还原