title: Deep-UV surface-enhanced resonance Raman scattering of adenine on aluminum nanoparticle arrays.
abstract: 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 label-free adenine molecules could be detected reproducibly in real time. Zeptomole (~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.
authors.affiliation: Laboratory of Metal Physics and Technology, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland. shankar.jha@mat.ethz.ch
authors.forename: Shankar K
authors.initials: SK
authors.lastname: Jha
authors.forename: Zeeshan
authors.initials: Z
authors.lastname: Ahmed
authors.forename: Mario
authors.initials: M
authors.lastname: Agio
authors.forename: Yasin
authors.initials: Y
authors.lastname: Ekinci
authors.forename: Jörg F
authors.initials: JF
authors.lastname: Löffler
mesh_terms: D000225:Adenine / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D000535:Aluminum; D000225:Adenine