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

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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.