Cinel, N. A.Butun, S.Özbay, Ekmel2015-07-282015-07-282012-01-201094-4087http://hdl.handle.net/11693/12337We present a label-free, optical nano-biosensor based on the Localized Surface Plasmon Resonance (LSPR) that is observed at the metaldielectric interface of silver nano-disk arrays located periodically on a sapphire substrate by Electron-Beam Lithography (EBL). The nano-disk array was designed by finite-difference and time-domain (FDTD) algorithm-based simulations. Refractive index sensitivity was calculated experimentally as 221-354 nm/RIU for different sized arrays. The sensing mechanism was first tested with a biotin-avidin pair, and then a preliminary trial for sensing heat-killed Escherichia coli (E. coli) O157:H7 bacteria was done. Although the study is at an early stage, the results indicate that such a plasmonic structure can be applied to bio-sensing applications and then extended to the detection of specific bacteria species as a fast and low cost alternative. © 2012 Optical Society of America.EnglishBacteriaBiosensorsElectron Beam LithographyElectron BeamsEscherichia ColiInterfaces (materials)PlasmonsRefractive IndexSapphireArticle10.1364/OE.20.002587