采用一种简易的化学置换反应方法在泡沫镍基底上生长花针状的金纳米结构,并将其作为表面增强拉曼散射(SERS)基底,主要研究置换时间对SERS基底性能的影响。采用COMSOL Multiphysics仿真软件对金纳米粒子高度分别为100,150,175,200 nm的基底进行电磁增强仿真,得到最大电场强度分别为20.112,29.060,24.766,21.382 V/m,计算得到增强因子分别为1.64×10 ⁵、7.13×10 ⁵、3.76×10 ⁵和2.09×10 ⁵。使用罗丹明6G(R6G)溶液作为探针分子,对不同置换时间下的泡沫镍镀金基底进行拉曼表征、检测极限测试以及拉曼mapping测试。测试结果表明,置换时间为10 min的基底增强效果是最佳的,对R6G分子的检测浓度可以达到10 ^-8 mol·L ^-1,在613,774,1364 cm ^-1这三个R6G分子的拉曼位移特征峰处的相对标准偏差值分别为11.3%、10.9%和11.9%,说明基底具有较好的均匀性,增强因子为1.04×10 ⁵。

A simple chemical substitution reaction method is used to grow needle-like gold nanostructures on nickel foam substrates, which are used as surface-enhanced Raman scattering (SERS) substrates to study the effect of substitution time on the properties of SERS substrates. COMSOL Multiphysics simulation software is used to simulate the electromagnetic enhancement of gold nanoparticles with the heights of 100,150,175,200 nm, respectively, and the maximum electric field intensity is 20.112, 29.060, 24.766, 21.382 V/m, respectively. The enhanced factors are 1.64×10 ⁵, 7.13×10 ⁵, 3.76×10 ⁵, and 2.09×10 ⁵, respectively. Using rhodamine 6G (R6G) solution as probe molecule, Raman characterization, detection limit test, and Raman mapping test are carried out on the nickel foam gold-plated substrate at different replacement times. The test results show that the substrate with displacement time of 10 min has the best enhancement effect, and the detection concentration of R6G molecule can reach 10 ^-8 mol·L ^-1, RSD (Relative Standard Deviation) values at the characteristic peaks of Raman shift of 613, 774, and 1364 cm ^-1 are 11.3%, 10.9%, and 11.9%, respectively. It shows that the substrate has good uniformity, the enhancement factor is 1.04×10 ⁵.