Open AccessLabel-free and selective nonlinear fiber-optical biosensing
Author(s) -
Johan Raunkjær Ott,
Mikkel Heuck,
Christian Agger,
Per Rasmussen,
Ole Bang
Publication year - 2008
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.16.020834
Subject(s) - biosensor , optical fiber , materials science , sensitivity (control systems) , fiber optic sensor , optics , photonic crystal fiber , surface plasmon resonance , wavelength , fiber , modulational instability , biomolecule , dispersion (optics) , nonlinear system , optoelectronics , nanotechnology , physics , electronic engineering , engineering , quantum mechanics , nanoparticle , composite material
We demonstrate that the inherent nonlinearity of a microstructured optical fiber (MOF) may be used to achieve label-free selective biosensing, thereby eliminating the need for post-processing of the fiber. This first nonlinear biosensor utilizes a change in the modulational instability (MI) gain spectrum (a shift of the Stokes- or anti-Stokes wavelength) caused by the selective capture of biomolecules by a sensor layer immobilised on the walls of the holes in the fiber. We find that such changes in the MI gain spectrum can be made detectable, and that engineering of the dispersion is important for optimizing the sensitivity. The nonlinear sensor shows a sensitivity of around 10.4 nm/nm, defined as the shift in resonance wavelength per nm biolayer, which is a factor of 7.5 higher than the hitherto only demonstrated label-free MOF biosensor.