Optical fiber biosensors utilizing turnaround point long period gratings with self-assembled polymer coatings

POLY 25

Erika Gifford, elming@vt.edu1, Zhiyong Wang, zhwang@vt.edu2, Siddharth Ramachandran, sidr@ofsoptics.com3, and James R. Heflin, rheflin@vt.edu1. (1) Department of Physics, Virginia Tech, Blacksburg, VA 24061, (2) Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061, (3) OFS Laboratories, 25 Schoolhouse Rd, Somerset, NJ 08873
Ionic self-assembled multilayers (ISAMs) adsorbed on optical fiber long period gratings (LPGs) can serve as inexpensive, robust, portable biosensor platforms. The ISAM technique is a layer-by-layer deposition technique that creates thin films on the nanoscale level. The combination of ISAMs with LPGs yields exceptional sensitivity of the optical fiber transmission spectrum. We have shown theoretically that the resonant wavelength shift for a thin-film coated LPG can be caused by the variation of the film's refractive index and/or the variation of the thickness of the film. We have experimentally demonstrated that the fabrication of nm-thick ISAM films deposited on LPGs induce shifts in the resonant wavelength of >1.6 nm per nm of thin film. We have further demonstrated that ISAM-coated LPGs can function effectively as biosensors by using the biotin-streptavidin system and by using the Bacillus anthracis (Anthrax) protective antigen (PA) antibody-PA system. The results confirm that ISAM-LPGs yield a reusable, thermally-stable, and robust platform for designing and building efficient optical biosensors.
 

Polymers in Biosensors and Biochips
8:30 AM-12:10 PM, Sunday, 10 September 2006 San Francisco Marriott -- Salon 12/13, Oral

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006