Quan Jiamin, Zhu Yong, Zhang Jie, Li Junyin, Wang Ning
Appl Opt. 2017 Jul 10;56(20):5751-5760. doi: 10.1364/AO.56.005751.
We report an effective and simple method to further enhance the surface-enhanced Raman scattering (SERS) by silver (Ag) nanoparticles (AgNPs) self-assembling into the nanogaps of an Ag nanoisland (AgNIs). The AgNIs prepared by dewetting of Ag film created a nanorough surface, which induced the Ag nanoparticles to regularly deposit into the nanogaps. AgNPs and AgNIs samples were also prepared for comparative analysis. Their SERS activities were investigated theoretically and experimentally. Experimental enhancement factors (EFs) for AgNPs, AgNIs, and AgNPs decorated AgNIs substrate (AgNPs-AgNIs) were ∼10, ∼10, ∼10, respectively, with relative standard deviation (RSD) of 66.1%, 12.9%, and 13.2%. Remarkable enhancement (EF≈10) and excellent reproducibility (RSD=13.2%) indicated the AgNPs-AgNIs had a high potential in practical application. Electromagnetic simulation using COMSOL Multiphysics demonstrated that the additional enhancement of the SERS effect could be mainly attributed to the improvement of the local electromagnetic field. Moreover, the deposition process of Ag nanoparticles was analyzed in detail to understand the reproducibility of AgNPs-AgNIs.
我们报道了一种有效且简单的方法，可通过银（Ag）纳米颗粒（AgNPs）自组装到银纳米岛（AgNIs）的纳米间隙中来进一步增强表面增强拉曼散射（SERS）。通过银膜去湿制备的AgNIs产生了纳米粗糙表面，这促使Ag纳米颗粒规则地沉积到纳米间隙中。还制备了AgNPs和AgNIs样品用于对比分析。对它们的SERS活性进行了理论和实验研究。AgNPs、AgNIs以及AgNPs修饰的AgNIs基底（AgNPs-AgNIs）的实验增强因子（EFs）分别约为10、10、10，相对标准偏差（RSD）分别为66.1%、12.9%和13.2%。显著的增强效果（EF≈10）和出色的重现性（RSD = 13.2%）表明AgNPs-AgNIs在实际应用中具有很高的潜力。使用COMSOL Multiphysics进行的电磁模拟表明，SERS效应的额外增强主要归因于局部电磁场的改善。此外，详细分析了Ag纳米颗粒的沉积过程，以了解AgNPs-AgNIs的重现性。
