Near-field enhanced ultraviolet resonance Raman spectroscopy using aluminum bow-tie nano-antenna

An aluminum bow-tie nano-antenna is combined with the resonance Raman effect in the deep ultraviolet to dramatically increase the sensitivity of Raman spectra to a small volume of material, such as benzene used here. We further demonstrate gradient-field Raman peaks for several strong infrared modes. We achieve a gain of similar to 10(5) in signal intensity from the near field enhancement due to the surface plasmon resonance in the aluminum nanostructure. The on-line resonance enhancement contributes another factor of several thousands, limited by the laser line width. Thud, an overall gain of hundreds of million is achieved. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4746747]