Journal of the American Chemical Society, Vol.134, No.4, 1966-1969, 2012
Deep-UV Surface-Enhanced Resonance Raman Scattering of Adenine on Aluminum Nanoparticle Arrays
We report the ultrasensitive detection of adenine using deep-UV surface-enhanced resonance Raman scattering on aluminum nanostructures. Well-defined Al nanoparticle arrays fabricated over large areas using extreme-UV interference lithography exhibited sharp and tunable plasmon resonances in the UV and deep-UV wavelength ranges. Theoretical modeling based on the finite-difference time-domain method was used to understand the near-field and far-field optical properties of the nanoparticle arrays. Raman measurements were performed on adenine molecules coated uniformly on the Al nanoparticle arrays at a laser excitation wavelength of 257.2 nm. With this technique, less than 10 amol of labelfree adenine molecules could be detected reproducibly in real time. Zeptomole (similar to 30 000 molecules) detection sensitivity was readily achieved proving that deep-UV surface-enhanced resonance Raman scattering is an extremely sensitive tool for the detection of biomolecules.