Gap-tunable Ag-nanorod arrays on alumina nanotip arrays as effective SERS substrates
Gap-tunable Ag-nanorod arrays on alumina nanotip arrays as effective SERS substrates
复制标题
氧化铝纳米尖阵列上的间隙可调银纳米棒阵列作为有效的 SERS 基底
DOI：
10.1039/c3tc30669k
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Hu, Xiaoye
中科院分区：
文献类型：
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作者：
Sun, Kexi;Meng, Guowen;Hu, Xiaoye
通过阳极氧化铝箔向下生长和磷酸刻蚀扩孔的重复工艺，在氧化铝模板的六角形圆锥孔的连接处获得了长度可调的大面积氧化铝纳米尖端阵列。通过在氧化铝纳米针尖阵列上顶视溅射银，在氧化铝纳米针尖上获得了六方图案的银纳米棒阵列(Ag-NRs)，在锥形孔内表面的上缘获得了均匀分布的银纳米颗粒(Ag-NPs)，由于最近相邻的Ag-NRs之间和相邻的Ag-NPs之间有高密度的亚10 nm间隙，它们表现出很强的表面增强拉曼散射(SERS)活性。通过调节银的溅射时间，得到的纳米结构具有最佳的表面增强拉曼散射增强因子∼3.2×10~7。SERS测量表明，所制备的大规模银纳米结构可以作为高灵敏度和可重复性的SERS衬底。有限元计算也证实了所制备的衬底具有良好的SERS活性。通过用单-6-硫代-β-环糊精修饰的Ag-NR阵列，多氯联苯的同系物PCB77的表面增强拉曼光谱检测下限达到10−6M，显示了基于表面增强拉曼光谱快速检测全球环境有害物质痕量多氯联苯的潜力。
Large area arrays of length-tunable alumina nanotips on the joints of hexagonally patterned conical-pores in an anodic aluminum oxide (AAO) template are achieved via a repeated process of anodizing Al foil for pore growth downwards and phosphoric acid etching for pore-widening. By top-view sputtering Ag on the alumina nanotip arrays, hexagonally patterned arrays of Ag-nanorods (Ag-NRs) on the alumina nanotips and uniformly distributed Ag-nanoparticles (Ag-NPs) on the upper rim of the inner surface of the conical-pores are obtained and they exhibit strong surface-enhanced Raman scattering (SERS) activity due to the high density of sub-10 nm gaps between the nearest neighboring Ag-NRs and between the adjacent Ag-NPs. The resultant nanostructures are tailored to attain an optimal SERS enhancement factor of ∼3.2 × 107 by tuning the Ag-sputtering duration. SERS measurements demonstrate that the as-fabricated large-scale Ag-nanostructures can serve as highly sensitive and reproducible SERS substrates. Finite element method calculation also confirms that the fabricated substrates possess excellent SERS activity. By modifying the Ag-NR arrays with mono-6-thio-β-cyclodextrin, the SERS detection limit of PCB-77 (a congener of polychlorinated biphenyls (PCBs)) reaches 10−6 M, showing potential in SERS-based rapid detection of trace PCBs, a kind of global environmental hazardous material.