Open AccessEllipsometry study on gold-nanoparticle-coated gold thin film for biosensing application
Author(s) -
Rakesh S. Moirangthem,
Yia-Chung Chang,
PeiKuen Wei
Publication year - 2011
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.2.002569
Subject(s) - biosensor , surface plasmon resonance , ellipsometry , materials science , colloidal gold , plasmon , nanoparticle , thin film , nanotechnology , surface plasmon , total internal reflection , optoelectronics , optics , physics
The amplified plasmonic response from various distributions of gold nanoparticles (AuNPs) coated on top of gold thin film was studied via ellipsometry under total internal reflection mode. The surface plasmon resonance dip can be tuned from the visible to near infrared by simply varying the AuNP concentration. Theoretical modeling based on effective medium theory with a multi-slice model has been employed to fit the experimental results. Additionally, this experimental tool has been further extended to study bio-molecular interactions with metal surfaces as well as in studying protein-protein interaction without any labeling. Hence, this technique could provide a non-destructive way of designing tunable label-free optical biosensors with very high sensitivity.