Development of Highly Sensitive DNA Microarray Sensor Based on Periodic Metallic Nanostructures

利用电子束光刻和剥离技术在玻璃衬底上制备了高质量的周期性金属纳米结构，其精度为几个纳米。这种制造的前所未有的精确度使得能够观察到光谱均匀的等离子体共振，这些共振对纳米颗粒介电环境中的纳米级变化高度敏感，并且由于局部化而表现出强烈的等离子体近场增强。这些特性对于各种光学传感应用都是有利的。例如，由于金属表面局部介电常数的变化，等离子体共振的光谱红移使得DNA杂交过程得以阐明，并为在不久的将来创建低成本的DNA微分析阵列开辟了道路。高局域场强增强使等离子体纳米结构的化学和生物传感成为可能，来自吡啶分子的表面增强拉曼散射(SERS)信号被放大了高达10^lt；10&gt；倍。此外，还观察到了金属金在可见光波段的强烈的非线性光致发光。在这里，我们介绍了这些和其他效应的实验和理论研究，以及影响金属纳米结构制造精度和设计指南的问题。最后，提出了一种利用激光干涉光刻技术制备大规模周期性金属纳米结构的新方法。

High-quality periodic metallic nanostructures were fabricated with accuracy of a few nanometers on glass substrates by electron beam lithography and lift off techniques. The unprecedented accuracy of the fabrication has enabled observation of spectrally homogeneous plasmonic resonances that are highly sensitive to nanoscale variations in dielectric environment of the nanoparticles, and exhibit strong plasmonic near-field enhancement due to localization. These features are favorable for various optical sensing applications. For example, spectral red-shift of the plasmonic resonance due to local dielectric permittivity variations at the metals' surface has allowed elucidation of DNA hybridization process, and opened ways for the creation of low-cost DNA micro-analysis arrays in the near future. High local field intensity enhancement has enabled chemical and bio-sensing with plasmonic nanostructures, as is evidenced by the achieved amplification of Surface-Enhanced Raman Scattering (SERS) signal from Pyridine molecules by up to 10^<10> times. Also, intense non-linear photoluminescence from metallic gold at visible wavelengths was observed. Here we present experimental and theoretical studies of these and other effects, as well as issues affecting the fabrication accuracy and design guidelines for the metallic nanostructures. Finally, a novel methodology for the fabrication of large-scale periodic metallic nanostructures by laser interference lithography is presented.