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为使表面增量拉曼散射(SERS)衬底的制备方法简单快速且提高的基底增强效果,采用置换反应的制备方法,用锌片和硝酸银反应制备出微米银结构SERS活性基底,其具有稳定性好,易保存,制备方法简单,过程快速等特点。用扫描电子显微镜观察得银微米材料表面形貌呈均匀对称的树枝状结构。实验中控制置换反应的时间分别为40,50,60s时,得到的树枝状银微米材料的长度分别为3,5,10μm左右,分支分别为700nm,2μm,3μm,发现随着置换反应的时间的增长,微米银树枝及分枝的长度越长,且树枝分枝上逐渐长出纳米级“树叶”结构,使得微米级银树枝表面具有纳米结构。并且将微米银材料置于硅片上作为SERS衬底,并以罗丹明6G为探针分子,用激发波长为1 064nm的傅里叶变换拉曼光谱仪检测,研究其在表面增强拉曼光谱中的应用,结果表明树枝状银微米材料有很好的SERS特性,其中置换反应时间为40s时制备的微米银树枝的增强效果最佳,其增强因子可达到103左右,并且采用用表面活性剂PVP处理硅片的方法后,保持其他条件不变,微米银衬底的SERS增强效果得到进一步加强,增强因子达到104左右。此外,将树枝状银微米材料用水可封存数月,且实验结果的重复性较好。
In order to make the surface enhanced Raman scattering (SERS) substrate preparation method simple and fast and improve the substrate enhancement effect, the preparation method of the displacement reaction was used to prepare the SERS active substrate with the silver microstructure with the reaction of zinc flake and silver nitrate, Good stability, easy to save, preparation method is simple, fast process and so on. Scanning electron microscopy showed that the surface morphology of silver micron material was uniform symmetrical dendritic structure. The length of dendritic silver micro-material obtained at the time of 40,50,60 and 60s were respectively about 3, 5 and 10μm, the branches were 700nm, 2μm and 3μm respectively. It was found that with the time of the replacement reaction The longer the length of micron silver branches and branches, the longer the branch branches grow nanometer level “leaves ” structure, making the surface of micron silver branches have nanostructures. The micro-silver material was placed on a silicon wafer as a SERS substrate, and rhodamine 6G was used as a probe molecule, and was detected by a Fourier transform Raman spectrometer with an excitation wavelength of 1,064 nm. The surface enhanced Raman spectroscopy The results showed that the dendritic silver micro-material has good SERS characteristics. The micro silver dendrites prepared by the displacement reaction time of 40s had the best enhancement effect, and the enhancement factor could reach about 103, After processing the silicon wafer, the SERS enhancement effect of the silver substrate was further strengthened and the enhancement factor was about 104, keeping the other conditions unchanged. In addition, the dendritic silver material can be stored for several months with water, and the repeatability of the experimental results is better.