具有分形结构Ag纳米衬底的荧光增强效应

利用电化学沉积方法,制备出具有分形结构的Ag纳米荧光增强衬底。实验中,采用532nm连续光激发居于Ag纳米结构衬底表面附近的罗丹明6G(Rh6G)荧光分子,结果表明,具有分形结构的Ag纳米金属衬底对沉积在其表面的Rh6G分子表现出明显的荧光增强效应。根据局域场增强理论对所得实验结果进行分析,经过电化学方法制备出的分形Ag纳米结构,在外电磁场激发下能够形成较强的局域电磁场分布,从而有效地激发Rh6G荧光分子,增强其荧光辐射强度。

Fluorescence enhancement from the fractal Ag nanostructured surface

The fluorescence emission of fluorophore molecules in the vicinity of nano-structured metal surface can be enhanced through local electromagnetic field with help of surface plasmon resonance.The fluorescence enhancement effect is very sensitive to the topography and dielectric properties of metal substrate.In current work,metal substrates with Ag fractal structure are prepared through electrochemical reduction followed by physical deposition.The surface enhanced fluorescence of Rh6G monolayer molecules deposited on the prepared complex substrates is investigated using continuous laser with wavelength of 532 nm.The experimental results show that the Ag fractal structure presents stronger fluorescence enhancement for the Rh6G molecules deposited on it.According to the local field enhancement theory,the experimental results indicate that the prepared Ag fractal nanostructure can form strong local electromagnetic field under the excitation of external electromagnetic field,and then excite the Rh6G fluorophore molecules effectively to enhance the fluorescence intensity.