Rindorf, Lars Henning2; Jensen, Jesper Bo2; Dufva, Hans Martin5; Pedersen, Lars Hagsholm6; Hoiby, Poul Erik6; Bang, Ole2
1 Fibers & Nonlinear Optics, Department of Photonics Engineering, Technical University of Denmark2 Department of Photonics Engineering, Technical University of Denmark3 Micro Array Technology, Department of Micro- and Nanotechnology, Technical University of Denmark4 Department of Micro- and Nanotechnology, Technical University of Denmark5 Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics, Center, Technical University of Denmark6 unknown
We present experimental results showing that long-period gratings in photonic crystal fibers can be used as sensitive biochemical sensors. A layer of biomolecules was immobilized on the sides of the holes of the photonic crystal fiber and by observing the shift in the resonant wavelength of a long-period grating it was possible to measure the thickness of the layer. The long-period gratings were inscribed in a large-mode area silica photonic crystal fiber with a CO2 laser. The thicknesses of a monolayer of poly-L-lysine and double-stranded DNA was measured using the device. We find that the grating has a sensitivity of approximately 1.4nm/1nm in terms of the shift in resonance wavelength in nm per nm thickness of biomolecule layer.
Optics Express, 2006, Vol 14, Issue 18, p. 8224-8231