Browsing by Subject "Surface-enhanced infrared spectroscopy"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Exploiting native Al2O3 for multispectral aluminum plasmonics(American Chemical Society, 2014) Ayas S.; Topal, A. E.; Cupallari, A.; Güner, H.; Bakan, G.; Dana, A.Aluminum, despite its abundance and low cost, is usually avoided for plasmonic applications due to losses in visible/infrared regimes and its interband absorption at 800 nm. Yet, it is compatible with silicon CMOS processes, making it a promising alternative for integrated plasmonic applications. It is also well known that a thin layer of native Al2O3 is formed on aluminum when exposed to air, which must be taken into account properly while designing plasmonic structures. Here, for the first time we report exploitation of the native Al2O3 layer for fabrication of periodic metal-insulator-metal (MIM) plasmonic structures that exhibit resonances spanning a wide spectral range, from the near-ultraviolet to mid-infrared region of the spectrum. Through fabrication of silver nanoislands on aluminum surfaces and MIM plasmonic surfaces with a thin native Al2O3 layer, hierarchical plasmonic structures are formed and used in surface-enhanced infrared spectroscopy (SEIRA) and surface-enhanced Raman spectrocopy (SERS) for detection of self-assembled monolayers of dodecanethiol. (Chemical Equation Presented). © 2014 American Chemical Society.Item Open Access Universal infrared absorption spectroscopy using uniform electromagnetic enhancement(American Chemical Society, 2016) Ayas S.; Bakan, G.; Ozgur E.; Celebi, K.; Dana, A.Infrared absorption spectroscopy has greatly benefited from the electromagnetic field enhancement offered by plasmonic surfaces. However, because of the localized nature of plasmonic fields, such field enhancements are limited to nanometer-scale volumes. Here, we demonstrate that a relatively small, but spatially uniform field enhancement can yield a superior infrared detection performance compared to the plasmonic field enhancement exhibited by optimized infrared nanoantennas. A specifically designed CaF2/Al thin film surface is shown to enable observation of stronger vibrational signals from the probe material, with wider bandwidth and a deeper spatial extent of the field enhancement as compared to such plasmonic surfaces. It is demonstrated that the surface structure presented here can enable chemically specific and label-free detection of organic monolayers using surface-enhanced infrared spectroscopy, indicating a great potential in highly sensitive yet cost-effective biomolecular sensing applications.