Shao Feng, Lu Zhicheng, Liu Chen, Han Heyou, Chen Kun, Li Wentao, He Qigai, Peng Hui, Chen Juanni
State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University , Wuhan 430070, China.
ACS Appl Mater Interfaces. 2014 May 14;6(9):6281-9. doi: 10.1021/am4045212. Epub 2014 Jan 6.
A three-dimensional (3D) biomimetic SERS substrate with hierarchical nanogaps was formed on the bioscaffold arrays of cicada wings by one-step and reagents-free ion-sputtering techniques. This approach requires a minimal fabrication effort and cost and offers Ag nanoislands and Ag nanoflowers with four types of nanogaps (<10 nm) on the chitin nanopillars to generate a high density of hotspots (∼2000/μm2). The 3D biomimetic substrate shows a low detection limit to Rhodamine 6G (10(-13) M), high average enhancement factor (EF, 5.8×10(7)), excellent signal uniformity (5.4%), good stability, and suitability in biosensing. Furthermore, the finite-difference time-domain (FDTD) electric-field-distribution simulations illustrate that the 3D biomimetic SERS substrate provides the high-density hotspot area within a detection volumem, resulting in enormous SERS enhancement. In addition, the conspicuous far-field plasmon resonance peaks were not found to be a strong requirement for a high EF in 3D biomimetic substrates. Additionally, the novel substrate was applied in label-free animal viruses detection and differentiation with small amounts (1.0 μL) and low concentrations of analyte (1×10(3) PFU/mL), and it exhibited potential as an effective SERS platform for virus detection and sensing.
通过一步无试剂离子溅射技术，在蝉翼的生物支架阵列上形成了具有分级纳米间隙的三维（3D）仿生表面增强拉曼散射（SERS）基底。这种方法所需的制备工作量和成本极低，在几丁质纳米柱上提供了具有四种类型纳米间隙（<10 nm）的银纳米岛和银纳米花，以产生高密度的热点（约2000/μm²）。该3D仿生基底对罗丹明6G显示出低检测限（10⁻¹³ M）、高平均增强因子（EF，5.8×10⁷）、出色的信号均匀性（5.4%）、良好的稳定性以及在生物传感方面的适用性。此外，时域有限差分（FDTD）电场分布模拟表明，3D仿生SERS基底在检测体积内提供了高密度的热点区域，从而实现了巨大的SERS增强。此外，在3D仿生基底中，明显的远场等离子体共振峰并非高EF的强烈要求。此外，该新型基底被应用于无标记动物病毒的检测和区分，样品量少（1.0 μL）且分析物浓度低（1×10³ PFU/mL），并展现出作为病毒检测和传感有效SERS平台的潜力。
