Purwidyantri Agnes, Hsu Chih-Hsien, Yang Chia-Ming, Prabowo Briliant Adhi, Tian Ya-Chung, Lai Chao-Sung
Research Unit for Clean Technology, Indonesian Institute of Sciences Bandung Indonesia.
Biosensor Group, Chang-Gung University Taoyuan Taiwan
RSC Adv. 2019 Feb 8;9(9):4982-4992. doi: 10.1039/c8ra10656h. eCollection 2019 Feb 5.
Unique structures of a gold island over nanospheres (AuIoN) featuring a three-dimensional (3D) nanostructure on a highly ordered two-dimensional (2D) array of nanospherical particles with different adhesion layers were fabricated as surface-enhanced Raman scattering (SERS) substrates. Ultra-thin Au was thermally evaporated onto PS nanospheres while aluminum oxide (AlO) was applied as an Au adhesion layer. The outcomes demonstrate that the higher metallic particle density and surface roughness supplied by the AlO provided larger interatomic bonding than a conventional adhesion layer, the highly-dispersive Cr. Nanosphere lithography (NSL) to deposit templating particles as small as ∼100 nm successfully created a simple initial roughening process which in turn boosted the localized surface plasmon resonance (LSPR) efficiency. So far, PS template deposition of a size less than 200 nm has been challenging, but here, through the use of a simple solvent ratio adjustment on drop-casting NSL, the novelty of natural lithography with downscaled properties as an alternative to the complexity of photolithography which is mostly conducted in the strict ambience of a clean room, is presented. SERS activity was primarily attributed to the synergistic effect of collective LSPRs from the AuIoN structure reinforcing the electromagnetic field, particularly in the crevices of two neighboring AuIoNs, as simulated by FDTD (Finite-Difference Time-Domain) computation. An AuIoN fabricated by the integration of AlO with thinner Au particles showed the optimum SERS activities with an improved enhancement factor of 1.51 × 10. Overall, a non-lithographic technique in tuning SERS hotspots and favorable characteristics of AlO for ultra-thin Au adhesion support, which can potentially be used in the fabrication of various devices, was demonstrated.
通过在具有不同粘附层的纳米球形颗粒的高度有序二维（2D）阵列上构建具有三维（3D）纳米结构的纳米球上的金岛（AuIoN）的独特结构，制备了表面增强拉曼散射（SERS）基底。将超薄金热蒸发到PS纳米球上，同时将氧化铝（AlO）用作金粘附层。结果表明，与传统粘附层Cr相比，AlO提供的更高金属颗粒密度和表面粗糙度提供了更大的原子间键合。纳米球光刻（NSL）用于沉积小至约100 nm的模板颗粒，成功创建了一个简单的初始粗糙化过程，进而提高了局部表面等离子体共振（LSPR）效率。到目前为止，尺寸小于200 nm的PS模板沉积一直具有挑战性，但在这里，通过在滴铸NSL上使用简单的溶剂比例调整，展示了具有缩小特性的自然光刻的新颖性，作为在洁净室严格环境中进行的大多复杂光刻的替代方案。SERS活性主要归因于来自AuIoN结构的集体LSPR增强电磁场的协同效应，特别是在两个相邻AuIoN的缝隙中，如通过有限差分时域（FDTD）计算模拟的那样。通过将AlO与更薄的金颗粒整合制备的AuIoN显示出最佳的SERS活性，增强因子提高到1.51×10。总体而言，展示了一种用于调节SERS热点的非光刻技术以及AlO对超薄金粘附支持的有利特性，其有可能用于各种器件的制造。
