Open AccessDual Kretschmann and Otto configuration fiber surface plasmon resonance biosensor
Author(s) -
Lixia Li,
Yuzhang Liang,
Jianye Guang,
Wenli Cui,
Xinpu Zhang,
JeanFrançois Masson,
Wei Peng
Publication year - 2017
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.25.026950
Subject(s) - surface plasmon resonance , refractive index , materials science , fiber optic sensor , optical fiber , optics , biosensor , surface plasmon , optoelectronics , indium tin oxide , resonance (particle physics) , fiber , localized surface plasmon , plasmon , thin film , nanotechnology , nanoparticle , physics , particle physics , composite material
We present a dual-resonance fiber surface plasmon resonance (SPR) sensor for biological analysis. The sensing element was fabricated by sequentially sputtering layers of indium tin oxide (ITO) (100 nm thickness) and Au (35 nm thickness) on the surface of an optical fiber. The refractive index dispersion effect of ITO material led to resonances in the near infrared and visible wavelength regions. The refractive index of ITO is larger than the optical fiber in visible spectral area (400 to 733nm), such that the structure is a typical Kretschmann configuration surface plasmon resonance sensor. However, an Otto configuration is observed in the near infrared area (NIR) due to the ITO refractive index being smaller than the fiber core. We characterized the sensor performance by measuring bulk refractive index (RI) sensitivity in the two configurations, which were 1345 nm/RIU in the Kretschmann configuration and 1100 nm/RIU in the Otto configuration. In addition, this sensor was applied for real-time and label-free monitoring of the IgG/anti-IgG biomolecular interaction. As a robust and ultra-compact SPR sensor, which possesses wide detection range and is highly sensitive, this fiber SPR sensor can be applied for real-time biological analysis and monitoring.