新型膜状金纳米活性基底的制备及拉曼光谱增强研究

贵金属纳米粒子作为增强基底已经广泛应用于表面增强拉曼光谱(SERS)研究，传统的贵金属纳米基底在制备方法、增强能力、准确性等方面仍有待改进和提高。采用一种简易、高效的方法制备出了一种具有膜状结构的新型金纳米增强基底：以聚乙烯吡咯烷酮(PVP)作保护剂和粘结剂，通过化学还原法制备金纳米基底。实验考察了还原剂种类、反应温度、体系pH和柠檬酸钠浓度对反应的影响，制备出增强效果最佳的新型膜状金纳米基底。利用罗丹明B作为探针分子，考察基底的SERS特征，其增强因子可达6.5×105。利用扫描电镜(SEM)对纳米粒子的结构进行了表征，结果表明其具有膜状结构，且比表面积大，利于分子的吸附。相比于传统的贵金属纳米基底，该实验所制备的新型膜状金纳米基底增强效果更佳、灵敏度和准确度更高，具有很大的应用前景。

The Preparation of the New Membrane-Like Gold Nanoparticles Substrate and the Study of Its Raman Spectroscopy

As enhanced substrates, precious metal nanoparticles have been widely used in the study of the SERS.The traditional precious metal nanoparticles were still to be improved in the preparation methods, enhancement ability and accuracy. In this paper, simple and efficient method was developed to prepare a new membrane-like nanoparticles substrate. PVP was used as protectant and binder, gold nanoparticles were perpared by chemical reduction method. The effects of the reaction conditions on the reaction were investigated, including species of reducing agent, the temperature of the reaction, pH of the reaction system and the concentration of reducing agent. In addition, a new membrane-like nanoparticles substrate which had the best enhanced effect was prepared. The SERS characteristic of the substrate was inspected by rhodamine B. Its enhancement factor could reach to 6.5×105.The shape of gold nanoparticles was characterized by SEM. The results showed that it has a membrane structure and a large specific surface area which is conducive to molecular absorption. Compared with the traditional precious metal nanoparticles substrate, the new membrane-like gold nanoparticles substrate had a better enhanced effect and higher detection sensitivity and accuracy. All in all, it has a wide application prospect.