Enhanced nanoplasmonic optical sensors with reduced substrate effect.
We present a straightforward method to double the refractive index sensitivity of surface-supported nanoplasmonic optical sensors by lifting the metal nanoparticles above the substrate by a dielectric nanopillar. The role of the pillar is to substantially decrease the spatial overlap between the substrate and the enhanced fields generated at plasmon resonance. Data presented for nanodisks and nanoellipsoids supported by pillars of varying heights are found to be in excellent agreement with electrodynamics simulations. The described concepts apply to multitude of plasmonic nanostructures, fabricated by top-down or bottom-up techniques, and are likely to further facilitate the development of novel nanooptical sensors for biomedicine and diagnostics.
Applied Physics, Chalmers University of Technology, 41296 Göteborg Sweden. alexd@chalmers.se
Alexandre
A
Dmitriev
Carl
C
Hägglund
Si
S
Chen
Hans
H
Fredriksson
Tavakol
T
Pakizeh
Mikael
M
Käll
Duncan S
DS
Sutherland
D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties
D012822:Silicon Dioxide