Daglar Bihter, Demirel Gokcen Birlik, Khudiyev Tural, Dogan Tamer, Tobail Osama, Altuntas Sevde, Buyukserin Fatih, Bayindir Mehmet
UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara, Turkey.
Nanoscale. 2014 Nov 7;6(21):12710-7. doi: 10.1039/c4nr03909b.
The melt-infiltration technique enables the fabrication of complex nanostructures for a wide range of applications in optics, electronics, biomaterials, and catalysis. Here, anemone-like nanostructures are produced for the first time under the surface/interface principles of melt-infiltration as a non-lithographic method. Functionalized anodized aluminum oxide (AAO) membranes are used as templates to provide large-area production of nanostructures, and polycarbonate (PC) films are used as active phase materials. In order to understand formation dynamics of anemone-like structures finite element method (FEM) simulations are performed and it is found that wetting behaviour of the polymer is responsible for the formation of cavities at the caps of the structures. These nanostructures are examined in the surface-enhanced-Raman-spectroscopy (SERS) experiment and they exhibit great potential in this field. Reproducible SERS signals are detected with relative standard deviations (RSDs) of 7.2-12.6% for about 10,000 individual spots. SERS measurements are demonstrated at low concentrations of Rhodamine 6G (R6G), even at the picomolar level, with an enhancement factor of ∼10(11). This high enhancement factor is ascribed to the significant electric field enhancement at the cavities of nanostructures and nanogaps between them, which is supported by finite difference time-domain (FDTD) simulations. These novel nanostructured films can be further optimized to be used in chemical and plasmonic sensors and as a single molecule SERS detection platform.
熔体渗透技术能够制造出复杂的纳米结构，可广泛应用于光学、电子学、生物材料和催化等领域。在此，首次在熔体渗透的表面/界面原理下制备出了海葵状纳米结构，这是一种非光刻方法。功能化的阳极氧化铝（AAO）膜用作模板以实现纳米结构的大面积制备，聚碳酸酯（PC）膜用作活性相材料。为了理解海葵状结构的形成动力学，进行了有限元方法（FEM）模拟，发现聚合物的润湿行为是结构帽部形成空洞的原因。在表面增强拉曼光谱（SERS）实验中对这些纳米结构进行了检测，结果表明它们在该领域具有巨大潜力。对于约10000个独立斑点，检测到的可重现SERS信号的相对标准偏差（RSD）为7.2 - 12.6%。在低浓度罗丹明6G（R6G）下，甚至在皮摩尔水平，也进行了SERS测量，增强因子约为10(11)。这种高增强因子归因于纳米结构空洞处及其之间纳米间隙的显著电场增强，时域有限差分（FDTD）模拟证实了这一点。这些新型纳米结构薄膜可进一步优化，用于化学和等离子体传感器以及作为单分子SERS检测平台。
