基于紫外光诱导的银/泡沫镍复合结构增强拉曼散射

Enhanced Raman Scattering of Silver/Foam Nickel Composite Structure Based on Ultraviolet Induction

采用基于紫外光诱导的金属间置换反应的方法制备出了银/泡沫镍复合结构基底,将其作为表面增强拉曼散射(SERS)基底。采用COMSOL Multiphysics仿真软件对银纳米粒子直径分别为43,53,63 nm的银/泡沫镍复合结构基底进行了电磁场分布和理论增强因子计算,得到最大电场强度分别为43.76,55.16,87.25 V/m,对应的增强因子分别为3.67×10^(6),9.26×10^(6),5.80×10^(7)。拉曼测试实验表明:反应溶液浓度为1.5 mol·L^(−1)、置换时间为120 min的银/泡沫镍复合结构基底的拉曼测试效果是最佳的,基底对罗丹明6G(R6G)的检测极限可以达到10^(−12) mol·L^(−1),计算得到增强因子为2.47×10^(9)。利用浓度为10^(−7) mol·L^(−1)的R6G作为探针分子,对银/泡沫镍复合结构基底进行拉曼均匀性测试,在613 cm^(−1)、1364 cm^(−1)这两个拉曼位移特征峰处的相对标准偏差值分别为14.5%和13.6%,说明基底具有较好的均匀性。

A method of displacement reaction between metals based on ultraviolet(UV)induction is employed to prepare a substrate of a silver/foam nickel composite structure,which is then used as the surface-enhanced Raman scattering(SERS)substrate.The simulation software COMSOL Multiphysics is utilized to calculate the electromagnetic field distributions and the theoretical enhancement factors for substrates composed of silver nanoparticles with diameters of 43 nm,53 nm,and 63 nm,respectively.The maximum electric field intensities obtained are 43.76 V/m,55.16 V/m,and 87.25 V/m,respectively,and the corresponding enhancement factors(EFs)are 3.67×10^(6),9.26×10^(6),and 5.80×10^(7),respectively.Raman tests show that the measurement effect of the prepared substrate of the silver/foam nickel composite structure is optimal when the concentration of the reaction solution is 1.5 mol·L^(−1)and the displacement time is 120 min.The detection limit of the substrate on rhodamine 6G(R6G)is as low as 10^(−12) mol·L^(−1)and the EF calculated reaches 2.47×10^(9).R6G with a concentration of 10^(−7) mol·L^(−1)is used as the probe molecule of Raman uniformity tests on the substrate of the silver/foam nickel composite structure.The relative standard deviation(RSD)values corresponding to the characteristic peaks at 613 cm^(−1)and 1364 cm^(−1)in the Raman shift spectrum are 14.5%and 13.6%,respectively,which indicates that the substrate enjoys favorable uniformity.