Study on the Metal-Enhanced Fluorescence of Dyes by Ag-Polyvinylpyrrolidone Nanocomposites
Study on the Metal-Enhanced Fluorescence of Dyes by Ag-Polyvinylpyrrolidone Nanocomposites
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DOI：
10.4028/www.scientific.net/jnanor.33.1
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发表时间：
2015-06
影响因子：
1.7
通讯作者：
Xin He;Zhu Lin;Z. Zhao;Ruihui He;Mei Zhang;H. Fan
中科院分区：
文献类型：
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作者：
Xin He;Zhu Lin;Z. Zhao;Ruihui He;Mei Zhang;H. Fan
本文研究了Ag纳米粒子或Ag- pvp纳米复合材料对罗丹明B和荧光素荧光性质的影响。不同浓度的银纳米颗粒可显著增强染料的荧光强度。Ag-PVP纳米复合材料进一步提高了材料的强度。结果表明，在2% Ag-PVP纳米复合材料的作用下，罗丹明B的增强率为36.5倍，荧光素在5% Ag-PVP纳米复合材料的作用下增强率为4.37倍。这种增强主要是由于光与银纳米粒子的相互作用提高了局部电磁场对染料的激发率。Ag-PVP纳米复合材料对染料的进一步荧光增强是由于PVP分子有效地将Ag纳米颗粒与染料分离。此外，还讨论了两种染料增强率的差异。染料的量子产率越低，银纳米粒子与染料吸收的重叠程度越高，增强比越大。该研究对提高快速医学或生物检测的灵敏度具有重要意义。
In this work, the effects of Ag nanoparticles or Ag-PVP nanocomposites on the fluorescence properties of rhodamine B and fluorescein were investigated. The fluorescence intensities of the dyes could be largely enhanced by Ag nanoparticles with various concentrations. Moreover, the intensities were further increased by Ag-PVP nanocomposites. The results show that the maximum enhancement ratio of 36.5 fold is achieved for rhodamine B in the presence of 2% Ag-PVP nanocomposites, as well as 4.37 fold for fluorescein with 5% Ag-PVP nanocomposites. The enhancement is believed to mainly be originated from the increased excitation rate of the dyes due to the local electromagnetic field which is improved by the interaction of light with Ag nanoparticles. The further fluorescence enhancement of the dyes by Ag-PVP nanocomposites is attributed to the effective separation of Ag nanoparticles from the dyes by PVP molecules. Additionally, the difference in the enhancement ratio of two dyes was also discussed. The lower quantum yield of the dye, as well as higher overlapped degree between Ag nanoparticles and the absorption of dye result in the larger enhancement ratio. The research could be meaningful for improving the sensitivity of rapidly medical or biological assays.