Open AccessSensitive biosensors using Fano resonance in single gold nanoslit with periodic grooves
Author(s) -
Kuang-Li Lee,
Shu-Han Wu,
ChiaWei Lee,
PeiKuen Wei
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.024530
Subject(s) - fano resonance , surface plasmon resonance , optics , biosensor , materials science , resonance (particle physics) , figure of merit , surface plasmon , optoelectronics , plasmon , nanotechnology , physics , nanoparticle , particle physics
Chip-based biosensors for sensitive label-free detection were fabricated and tested by using Fano-type resonant nanostructures. The sensor was composed of a 190 nm-thick gold nanoslit surrounded by 600-nm-period grooves. Transverse-magnetic polarized wave in these gold nanostructures generated asymmetrical resonant spectra due to the interference of broad-band cavity resonance in the single slit and narrow-band surface plasmon resonance on the periodic grooves. Compared to nanoslit arrays, such Fano-type sensor has a sharper resonance which yields a figure of merit up to 48. In addition, the crossed talk between sensing elements is reduced due to the Bragg reflection of the periodic grooves. A smaller detection separation down to 10 μm width was achieved. An antigen-antibody interaction experiment in aqueous environment verified the detection sensitivity in surface binding event.