Electron beam lithography designed silver nano-disks used as label free nano-biosensors based on localized surface plasmon resonance

Date
2012-01-20
Advisor
Instructor
Source Title
Optics Express
Print ISSN
1094-4087
Electronic ISSN
Publisher
Optical Society of America
Volume
20
Issue
3
Pages
2587 - 2597
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We 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.

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Keywords
Bacteria, Biosensors, Electron Beam Lithography, Electron Beams, Escherichia Coli, Interfaces (materials), Plasmons, Refractive Index, Sapphire
Citation
Published Version (Please cite this version)